#include <bits/stdc++.h>
#ifdef LOCAL
#include <debug.hpp>
#else
#define debug(...) void(0)
#endif

template <class T> std::istream& operator>>(std::istream& is, std::vector<T>& v) {
    for (auto& e : v) {
        is >> e;
    }
    return is;
}

template <class T> std::ostream& operator<<(std::ostream& os, const std::vector<T>& v) {
    for (std::string_view sep = ""; const auto& e : v) {
        os << std::exchange(sep, " ") << e;
    }
    return os;
}

template <class T, class U = T> bool chmin(T& x, U&& y) {
    return y < x and (x = std::forward<U>(y), true);
}

template <class T, class U = T> bool chmax(T& x, U&& y) {
    return x < y and (x = std::forward<U>(y), true);
}

template <class T> void mkuni(std::vector<T>& v) {
    std::ranges::sort(v);
    auto result = std::ranges::unique(v);
    v.erase(result.begin(), result.end());
}

template <class T> int lwb(const std::vector<T>& v, const T& x) {
    return std::distance(v.begin(), std::ranges::lower_bound(v, x));
}

#ifdef _MSC_VER
#include <intrin.h>
#endif

namespace atcoder {

namespace internal {

// @param n `0 <= n`
// @return minimum non-negative `x` s.t. `n <= 2**x`
int ceil_pow2(int n) {
    int x = 0;
    while ((1U << x) < (unsigned int)(n)) x++;
    return x;
}

// @param n `1 <= n`
// @return minimum non-negative `x` s.t. `(n & (1 << x)) != 0`
constexpr int bsf_constexpr(unsigned int n) {
    int x = 0;
    while (!(n & (1 << x))) x++;
    return x;
}

// @param n `1 <= n`
// @return minimum non-negative `x` s.t. `(n & (1 << x)) != 0`
int bsf(unsigned int n) {
#ifdef _MSC_VER
    unsigned long index;
    _BitScanForward(&index, n);
    return index;
#else
    return __builtin_ctz(n);
#endif
}

}  // namespace internal

}  // namespace atcoder

namespace atcoder {

template <class S,
          S (*op)(S, S),
          S (*e)(),
          class F,
          S (*mapping)(F, S),
          F (*composition)(F, F),
          F (*id)()>
struct lazy_segtree {
  public:
    lazy_segtree() : lazy_segtree(0) {}
    explicit lazy_segtree(int n) : lazy_segtree(std::vector<S>(n, e())) {}
    explicit lazy_segtree(const std::vector<S>& v) : _n(int(v.size())) {
        log = internal::ceil_pow2(_n);
        size = 1 << log;
        d = std::vector<S>(2 * size, e());
        lz = std::vector<F>(size, id());
        for (int i = 0; i < _n; i++) d[size + i] = v[i];
        for (int i = size - 1; i >= 1; i--) {
            update(i);
        }
    }

    void set(int p, S x) {
        assert(0 <= p && p < _n);
        p += size;
        for (int i = log; i >= 1; i--) push(p >> i);
        d[p] = x;
        for (int i = 1; i <= log; i++) update(p >> i);
    }

    S get(int p) {
        assert(0 <= p && p < _n);
        p += size;
        for (int i = log; i >= 1; i--) push(p >> i);
        return d[p];
    }

    S prod(int l, int r) {
        assert(0 <= l && l <= r && r <= _n);
        if (l == r) return e();

        l += size;
        r += size;

        for (int i = log; i >= 1; i--) {
            if (((l >> i) << i) != l) push(l >> i);
            if (((r >> i) << i) != r) push((r - 1) >> i);
        }

        S sml = e(), smr = e();
        while (l < r) {
            if (l & 1) sml = op(sml, d[l++]);
            if (r & 1) smr = op(d[--r], smr);
            l >>= 1;
            r >>= 1;
        }

        return op(sml, smr);
    }

    S all_prod() { return d[1]; }

    void apply(int p, F f) {
        assert(0 <= p && p < _n);
        p += size;
        for (int i = log; i >= 1; i--) push(p >> i);
        d[p] = mapping(f, d[p]);
        for (int i = 1; i <= log; i++) update(p >> i);
    }
    void apply(int l, int r, F f) {
        assert(0 <= l && l <= r && r <= _n);
        if (l == r) return;

        l += size;
        r += size;

        //for (int i = log; i >= 1; i--) {
            //if (((l >> i) << i) != l) push(l >> i);
            //if (((r >> i) << i) != r) push((r - 1) >> i);
        //}

        {
            int l2 = l, r2 = r;
            while (l < r) {
                if (l & 1) all_apply(l++, f);
                if (r & 1) all_apply(--r, f);
                l >>= 1;
                r >>= 1;
            }
            l = l2;
            r = r2;
        }

        for (int i = 1; i <= log; i++) {
            if (((l >> i) << i) != l) update(l >> i);
            if (((r >> i) << i) != r) update((r - 1) >> i);
        }
    }

    template <bool (*g)(S)> int max_right(int l) {
        return max_right(l, [](S x) { return g(x); });
    }
    template <class G> int max_right(int l, G g) {
        assert(0 <= l && l <= _n);
        assert(g(e()));
        if (l == _n) return _n;
        l += size;
        for (int i = log; i >= 1; i--) push(l >> i);
        S sm = e();
        do {
            while (l % 2 == 0) l >>= 1;
            if (!g(op(sm, d[l]))) {
                while (l < size) {
                    push(l);
                    l = (2 * l);
                    if (g(op(sm, d[l]))) {
                        sm = op(sm, d[l]);
                        l++;
                    }
                }
                return l - size;
            }
            sm = op(sm, d[l]);
            l++;
        } while ((l & -l) != l);
        return _n;
    }

    template <bool (*g)(S)> int min_left(int r) {
        return min_left(r, [](S x) { return g(x); });
    }
    template <class G> int min_left(int r, G g) {
        assert(0 <= r && r <= _n);
        assert(g(e()));
        if (r == 0) return 0;
        r += size;
        for (int i = log; i >= 1; i--) push((r - 1) >> i);
        S sm = e();
        do {
            r--;
            while (r > 1 && (r % 2)) r >>= 1;
            if (!g(op(d[r], sm))) {
                while (r < size) {
                    push(r);
                    r = (2 * r + 1);
                    if (g(op(d[r], sm))) {
                        sm = op(d[r], sm);
                        r--;
                    }
                }
                return r + 1 - size;
            }
            sm = op(d[r], sm);
        } while ((r & -r) != r);
        return 0;
    }

  private:
    int _n, size, log;
    std::vector<S> d;
    std::vector<F> lz;

    void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); }
    void all_apply(int k, F f) {
        d[k] = mapping(f, d[k]);
        if (k < size) lz[k] = composition(f, lz[k]);
    }
    void push(int k) {
        all_apply(2 * k, lz[k]);
        all_apply(2 * k + 1, lz[k]);
        lz[k] = id();
    }
};

}  // namespace atcoder

namespace hash_impl {

static constexpr unsigned long long mod = (1ULL << 61) - 1;

struct modint {
    modint() : _v(0) {}
    modint(unsigned long long v) {
        v = (v >> 61) + (v & mod);
        if (v >= mod) v -= mod;
        _v = v;
    }

    unsigned long long val() const { return _v; }

    modint& operator+=(const modint& rhs) {
        _v += rhs._v;
        if (_v >= mod) _v -= mod;
        return *this;
    }
    modint& operator-=(const modint& rhs) {
        if (_v < rhs._v) _v += mod;
        _v -= rhs._v;
        return *this;
    }
    modint& operator*=(const modint& rhs) {
        __uint128_t t = __uint128_t(_v) * rhs._v;
        t = (t >> 61) + (t & mod);
        if (t >= mod) t -= mod;
        _v = t;
        return *this;
    }
    modint& operator/=(const modint& rhs) { return *this = *this * rhs.inv(); }

    modint operator-() const { return modint() - *this; }

    modint pow(long long n) const {
        assert(0 <= n);
        modint x = *this, r = 1;
        while (n) {
            if (n & 1) r *= x;
            x *= x;
            n >>= 1;
        }
        return r;
    }
    modint inv() const { return pow(mod - 2); }

    friend modint operator+(const modint& lhs, const modint& rhs) { return modint(lhs) += rhs; }
    friend modint operator-(const modint& lhs, const modint& rhs) { return modint(lhs) -= rhs; }
    friend modint operator*(const modint& lhs, const modint& rhs) { return modint(lhs) *= rhs; }
    friend modint operator/(const modint& lhs, const modint& rhs) { return modint(lhs) /= rhs; }
    friend bool operator==(const modint& lhs, const modint& rhs) { return lhs._v == rhs._v; }
    friend bool operator!=(const modint& lhs, const modint& rhs) { return lhs._v != rhs._v; }
    friend std::ostream& operator<<(std::ostream& os, const modint& rhs) {
        os << rhs._v;
        return os;
    }

  private:
    unsigned long long _v;
};

uint64_t generate_base() {
    std::mt19937_64 mt(std::chrono::steady_clock::now().time_since_epoch().count());
    std::uniform_int_distribution<uint64_t> rand(2, mod - 1);
    return rand(mt);
}

modint base(generate_base());
std::vector<modint> power{1};

modint get_pow(int n) {
    if (n < int(power.size())) return power[n];
    int m = power.size();
    power.resize(n + 1);
    for (int i = m; i <= n; i++) power[i] = power[i - 1] * base;
    return power[n];
}

};  // namespace hash_impl

struct Hash {
    using mint = hash_impl::modint;
    mint x;
    int len;

    Hash() : x(0), len(0) {}
    Hash(mint x) : x(x), len(1) {}
    Hash(mint x, int len) : x(x), len(len) {}

    Hash& operator+=(const Hash& rhs) {
        x = x * hash_impl::get_pow(rhs.len) + rhs.x;
        len += rhs.len;
        return *this;
    }
    Hash operator+(const Hash& rhs) const { return Hash(*this) += rhs; }
    bool operator==(const Hash& rhs) const { return x == rhs.x and len == rhs.len; }
};

struct ReversibleHash {
    using mint = hash_impl::modint;
    mint x, rx;
    int len;

    ReversibleHash() : x(0), rx(0), len(0) {}
    ReversibleHash(mint x) : x(x), rx(x), len(1) {}
    ReversibleHash(mint x, mint rx, int len) : x(x), rx(rx), len(len) {}

    ReversibleHash rev() const { return ReversibleHash(rx, x, len); }

    ReversibleHash operator+=(const ReversibleHash& rhs) {
        x = x * hash_impl::get_pow(rhs.len) + rhs.x;
        rx = rx + rhs.rx * hash_impl::get_pow(len);
        len += rhs.len;
        return *this;
    }
    ReversibleHash operator+(const ReversibleHash& rhs) const { return ReversibleHash(*this) += rhs; }
    bool operator==(const ReversibleHash& rhs) const { return x == rhs.x and rx == rhs.rx and len == rhs.len; }
};

using ll = long long;

using namespace std;

namespace hash_impl {

std::vector<modint> power_sum{0};

modint get_pow_sum(int n) {
    if (n < int(power_sum.size())) return power_sum[n];
    get_pow(n - 1);
    int m = power_sum.size();
    power_sum.resize(n + 1);
    for (int i = m; i <= n; i++) power_sum[i] = power_sum[i - 1] + power[i - 1];
    return power_sum[n];
}

}  // namespace hash_impl

using mint = hash_impl::modint;
using S = ReversibleHash;

S op(S l, S r) { return l + r; }

S e() { return S(); }

S mapping(int l, S r) {
    auto add = hash_impl::get_pow_sum(r.len);
    if (l >= 0) {
        add *= l;
    } else {
        add *= hash_impl::mod + l;
    }
    return S(r.x + add, r.rx + add, r.len);
}

int composition(int l, int r) { return l + r; }

int id() { return 0; }

const int THRESHOLD = 32;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);

    int n, q, k, b;
    cin >> n >> q >> k >> b;
    vector<int> A(n);
    cin >> A;

    vector<S> init;
    for (int i = 0; i < n; i++) {
        if (A[i] >= 0) {
            init.emplace_back(A[i]);
        } else {
            init.emplace_back(hash_impl::mod + A[i]);
        }
    }
    atcoder::lazy_segtree<S, op, e, int, mapping, composition, id> seg(init);
    auto update = [&](int l, int r, int v) -> void { seg.apply(l, r, v); };
    vector<S> hashs{e()};
    for (int i = 0; i < n; i++) {
        int x = k * (i + 1) + b;
        if (x >= 0) {
            hashs.emplace_back(hashs.back() + S(x));
        } else {
            hashs.emplace_back(hashs.back() + S(hash_impl::mod + x));
        }
    }
    auto check = [&](int i, int len) -> int {
        if (len == 0) return true;
        auto R = seg.prod(i + 1, i + len + 1).x;
        auto L = seg.prod(i - len, i).rx;
        return R - L == hashs[len].x;
    };
    auto query = [&](int i) -> int {
        int lb = 0, ub = min(i, n - 1 - i) + 1;
        if (check(i, ub - 1)) return ub - 1;
        ub--;
        if (not check(i, 1)) return 0;
        lb++;
        if (lb < THRESHOLD and THRESHOLD < ub) (check(i, THRESHOLD) ? lb : ub) = THRESHOLD;
        if (ub - THRESHOLD > lb) (check(i, ub - THRESHOLD) ? lb : ub) = ub - THRESHOLD;
        while (ub - lb > 1) {
            int mid = (lb + ub) >> 1;
            (check(i, mid) ? lb : ub) = mid;
        }
        return lb;
    };

    for (; q--;) {
        int type;
        cin >> type;
        if (type == 1) {
            int l, r, v;
            cin >> l >> r >> v;
            update(--l, r, v);
        } else {
            int i;
            cin >> i;
            cout << query(--i) << "\n";
        }
    }
    return 0;
}