#include <bits/stdc++.h>

using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned;
// TODO: Dynamic ModInt

template<typename T>
constexpr T power(T a, u64 b) {
    T res {1};
    for (; b != 0; b /= 2, a *= a) {
        if (b % 2 == 1) {
            res *= a;
        }
    }
    return res;
}

template<u32 P>
constexpr u32 mulMod(u32 a, u32 b) {
    return 1ULL * a * b % P;
}

template<u64 P>
constexpr u64 mulMod(u64 a, u64 b) {
    u64 res = a * b - u64(1.L * a * b / P - 0.5L) * P;
    res %= P;
    return res;
}

template<typename U, U P>
requires std::unsigned_integral<U>
struct ModIntBase {
public:
    constexpr ModIntBase() : x {0} {}
    
    template<typename T>
    requires std::integral<T>
    constexpr ModIntBase(T x_) : x {norm(x_ % T {P})} {}
    
    constexpr static U norm(U x) {
        if ((x >> (8 * sizeof(U) - 1) & 1) == 1) {
            x += P;
        }
        if (x >= P) {
            x -= P;
        }
        return x;
    }
    
    constexpr U val() const {
        return x;
    }
    
    constexpr ModIntBase operator-() const {
        ModIntBase res;
        res.x = norm(P - x);
        return res;
    }
    
    constexpr ModIntBase inv() const {
        return power(*this, P - 2);
    }
    
    constexpr ModIntBase &operator*=(const ModIntBase &rhs) & {
        x = mulMod<P>(x, rhs.val());
        return *this;
    }
    
    constexpr ModIntBase &operator+=(const ModIntBase &rhs) & {
        x = norm(x + rhs.x);
        return *this;
    }
    
    constexpr ModIntBase &operator-=(const ModIntBase &rhs) & {
        x = norm(x - rhs.x);
        return *this;
    }
    
    constexpr ModIntBase &operator/=(const ModIntBase &rhs) & {
        return *this *= rhs.inv();
    }
    
    friend constexpr ModIntBase operator*(ModIntBase lhs, const ModIntBase &rhs) {
        lhs *= rhs;
        return lhs;
    }
    
    friend constexpr ModIntBase operator+(ModIntBase lhs, const ModIntBase &rhs) {
        lhs += rhs;
        return lhs;
    }
    
    friend constexpr ModIntBase operator-(ModIntBase lhs, const ModIntBase &rhs) {
        lhs -= rhs;
        return lhs;
    }
    
    friend constexpr ModIntBase operator/(ModIntBase lhs, const ModIntBase &rhs) {
        lhs /= rhs;
        return lhs;
    }
    
    friend constexpr std::ostream &operator<<(std::ostream &os, const ModIntBase &a) {
        return os << a.val();
    }
    
    friend constexpr bool operator==(ModIntBase lhs, ModIntBase rhs) {
        return lhs.val() == rhs.val();
    }
    
    friend constexpr bool operator!=(ModIntBase lhs, ModIntBase rhs) {
        return lhs.val() != rhs.val();
    }
    
    friend constexpr bool operator<(ModIntBase lhs, ModIntBase rhs) {
        return lhs.val() < rhs.val();
    }
    
private:
    U x;
};

template<u32 P>
using ModInt = ModIntBase<u32, P>;

template<u64 P>
using ModInt64 = ModIntBase<u64, P>;

constexpr u64 P = u64(1E18) + 9;
using Z = ModInt64<P>;

template<class Info, class Tag>
struct LazySegmentTree {
    int n;
    std::vector<Info> info;
    std::vector<Tag> tag;
    LazySegmentTree() : n(0) {}
    LazySegmentTree(int n_, Info v_ = Info()) {
        init(n_, v_);
    }
    template<class T>
    LazySegmentTree(std::vector<T> init_) {
        init(init_);
    }
    void init(int n_, Info v_ = Info()) {
        init(std::vector(n_, v_));
    }
    template<class T>
    void init(std::vector<T> init_) {
        n = init_.size();
        info.assign(4 << std::__lg(n), Info());
        tag.assign(4 << std::__lg(n), Tag());
        std::function<void(int, int, int)> build = [&](int p, int l, int r) {
            if (r - l == 1) {
                info[p] = init_[l];
                return;
            }
            int m = (l + r) / 2;
            build(2 * p, l, m);
            build(2 * p + 1, m, r);
            pull(p);
        };
        build(1, 0, n);
    }
    void pull(int p) {
        info[p] = info[2 * p] + info[2 * p + 1];
    }
    void apply(int p, const Tag &v) {
        info[p].apply(v);
        tag[p].apply(v);
    }
    void push(int p) {
        apply(2 * p, tag[p]);
        apply(2 * p + 1, tag[p]);
        tag[p] = Tag();
    }
    void modify(int p, int l, int r, int x, const Info &v) {
        if (r - l == 1) {
            info[p] = v;
            return;
        }
        int m = (l + r) / 2;
        push(p);
        if (x < m) {
            modify(2 * p, l, m, x, v);
        } else {
            modify(2 * p + 1, m, r, x, v);
        }
        pull(p);
    }
    void modify(int p, const Info &v) {
        modify(1, 0, n, p, v);
    }
    Info rangeQuery(int p, int l, int r, int x, int y) {
        if (l >= y || r <= x) {
            return Info();
        }
        if (l >= x && r <= y) {
            return info[p];
        }
        int m = (l + r) / 2;
        push(p);
        return rangeQuery(2 * p, l, m, x, y) + rangeQuery(2 * p + 1, m, r, x, y);
    }
    Info rangeQuery(int l, int r) {
        return rangeQuery(1, 0, n, l, r);
    }
    void rangeApply(int p, int l, int r, int x, int y, const Tag &v) {
        if (l >= y || r <= x) {
            return;
        }
        if (l >= x && r <= y) {
            apply(p, v);
            return;
        }
        int m = (l + r) / 2;
        push(p);
        rangeApply(2 * p, l, m, x, y, v);
        rangeApply(2 * p + 1, m, r, x, y, v);
        pull(p);
    }
    void rangeApply(int l, int r, const Tag &v) {
        return rangeApply(1, 0, n, l, r, v);
    }
    template<class F>
    int findFirst(int p, int l, int r, int x, int y, F &&pred) {
        if (l >= y || r <= x) {
            return -1;
        }
        if (l >= x && r <= y && !pred(info[p])) {
            return -1;
        }
        if (r - l == 1) {
            return l;
        }
        int m = (l + r) / 2;
        push(p);
        int res = findFirst(2 * p, l, m, x, y, pred);
        if (res == -1) {
            res = findFirst(2 * p + 1, m, r, x, y, pred);
        }
        return res;
    }
    template<class F>
    int findFirst(int l, int r, F &&pred) {
        return findFirst(1, 0, n, l, r, pred);
    }
    template<class F>
    int findLast(int p, int l, int r, int x, int y, F &&pred) {
        if (l >= y || r <= x) {
            return -1;
        }
        if (l >= x && r <= y && !pred(info[p])) {
            return -1;
        }
        if (r - l == 1) {
            return l;
        }
        int m = (l + r) / 2;
        push(p);
        int res = findLast(2 * p + 1, m, r, x, y, pred);
        if (res == -1) {
            res = findLast(2 * p, l, m, x, y, pred);
        }
        return res;
    }
    template<class F>
    int findLast(int l, int r, F &&pred) {
        return findLast(1, 0, n, l, r, pred);
    }
};

constexpr Z B = 1145141ULL;

struct Tag {
    Z add = 0ULL;
    
    void apply(const Tag &t) & {
        add += t.add;
    }
};

struct Info {
    Z s1 = 0ULL;
    Z s2 = 0ULL;
    Z c = 0ULL;
    Z p = 1ULL;
    
    void apply(const Tag &t) & {
        s1 += c * t.add;
        s2 += c * t.add;
    }
};

Info operator+(const Info &a, const Info &b) {
    Info c;
    c.s1 = a.s1 * b.p + b.s1;
    c.s2 = a.s2 + a.p * b.s2;
    c.c = a.c * b.p + b.c;
    c.p = a.p * b.p;
    return c;
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    int n, q, k, b;
    std::cin >> n >> q >> k >> b;
    
    std::vector<int> A(n);
    for (int i = 0; i < n; i++) {
        std::cin >> A[i];
        A[i] = 2 * A[i] - k * i;
    }
    b *= 2;
    
    LazySegmentTree<Info, Tag> seg(n);
    for (int i = 0; i < n; i++) {
        seg.modify(i, {i64(A[i]), i64(A[i]), 1ULL, B});
    }
    
    while (q--) {
        int o;
        std::cin >> o;
        if (o == 1) {
            int l, r, v;
            std::cin >> l >> r >> v;
            l--;
            seg.rangeApply(l, r, {i64(2 * v)});
        } else {
            int i;
            std::cin >> i;
            i--;
            
            int lo = 0, hi = std::min(i, n - 1 - i);
            while (lo < hi) {
                int r = (lo + hi + 1) / 2;
                auto al = seg.rangeQuery(i - r, i);
                auto ar = seg.rangeQuery(i + 1, i + 1 + r);
                if (al.s1 + al.c * i64(b) == ar.s2) {
                    lo = r;
                } else {
                    hi = r - 1;
                }
            }
            std::cout << lo << "\n";
        }
    }
    
    return 0;
}