#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)()> struct segtree {
  public:
    segtree() : segtree(0) {}
    explicit segtree(int n) : segtree(std::vector<S>(n, e())) {}
    explicit 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());
        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;
        d[p] = x;
        for (int i = 1; i <= log; i++) update(p >> i);
    }

    S get(int p) const {
        assert(0 <= p && p < _n);
        return d[p + size];
    }

    S prod(int l, int r) const {
        assert(0 <= l && l <= r && r <= _n);
        S sml = e(), smr = e();
        l += size;
        r += size;

        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() const { return d[1]; }

    template <bool (*f)(S)> int max_right(int l) const {
        return max_right(l, [](S x) { return f(x); });
    }
    template <class F> int max_right(int l, F f) const {
        assert(0 <= l && l <= _n);
        assert(f(e()));
        if (l == _n) return _n;
        l += size;
        S sm = e();
        do {
            while (l % 2 == 0) l >>= 1;
            if (!f(op(sm, d[l]))) {
                while (l < size) {
                    l = (2 * l);
                    if (f(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 (*f)(S)> int min_left(int r) const {
        return min_left(r, [](S x) { return f(x); });
    }
    template <class F> int min_left(int r, F f) const {
        assert(0 <= r && r <= _n);
        assert(f(e()));
        if (r == 0) return 0;
        r += size;
        S sm = e();
        do {
            r--;
            while (r > 1 && (r % 2)) r >>= 1;
            if (!f(op(d[r], sm))) {
                while (r < size) {
                    r = (2 * r + 1);
                    if (f(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;

    void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); }
};

}  // namespace atcoder

namespace hash_impl {

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

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

    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;

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

Hash e() { return Hash(); }

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);
    for (int& val : A) cin >> val;

    vector<int> D(n - 1);
    vector<Hash> init;
    for (int i = 0; i < n - 1; i++) {
        D[i] = A[i + 1] - A[i];
        init.emplace_back(D[i]);
    }
    atcoder::segtree<Hash, op, e> seg(init);
    vector<Hash> sum(n + 1);
    sum[0] = Hash();
    for (int i = 0; i < n; i++) sum[i + 1] = sum[i] + Hash(k);

    auto update = [&](int l, int r, int v) {
        if (l - 1 >= 0) {
            D[l - 1] += v;
            seg.set(l - 1, Hash(D[l - 1]));
        }
        if (r < n) {
            D[r - 1] -= v;
            seg.set(r - 1, Hash(D[r - 1]));
        }
    };
    auto query = [&](int i) -> int {
        int lb = 0, ub = min(i, n - 1 - i) + 1;
        if (ub == 1) return 0;
        if (D[i] + D[i - 1] != k + b) return 0;
        lb++;
        while (ub - lb > 1) {
            int mid = (lb + ub) >> 1;
            auto ls = seg.prod(i + 1, i + mid).x;
            auto rs = seg.prod(i - mid, i - 1).x;
            (ls + rs == sum[mid - 1].x ? 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;
}