#include<vector>
#include<cstdio>
#include<queue>
#define ull unsigned long long
#define di1 19491001
#define di2 13331

using namespace std;

const int N = 2e5 + 100;
int n, q, k, b, a[N];
ull ds1[N], ds2[N];

struct XD_tree {
    int sz[N << 2];
    pair <ull, ull> f[N << 2], g[N << 2];

    void up(int now) {
        f[now].first = f[now << 1].first * ds1[sz[now << 1 | 1]] + f[now << 1 | 1].first;
        f[now].second = f[now << 1].second * ds2[sz[now << 1 | 1]] + f[now << 1 | 1].second;

        g[now].first = g[now << 1 | 1].first * ds1[sz[now << 1]] + g[now << 1].first;
        g[now].second = g[now << 1 | 1].second * ds2[sz[now << 1]] + g[now << 1].second;
    }

    void build(int now, int l, int r) {
        sz[now] = r - l + 1;
        if (l == r) {
            f[now] = g[now] = make_pair(a[l] - a[l - 1], a[l] - a[l - 1]);
            return ;
        }
        int mid = (l + r) >> 1;
        build(now << 1, l, mid); build(now << 1 | 1, mid + 1, r);
        up(now);
    }

    void insert(int now, int l, int r, int x, int val) {
        if (l == r) {
            f[now].first += val; f[now].second += val;
            g[now].first += val; g[now].second += val;
            return ;
        }
        int mid = (l + r) >> 1;
        if (x <= mid) insert(now << 1, l, mid, x, val);
            else insert(now << 1 | 1, mid + 1, r, x, val);
        up(now);
    }

    pair <ull, ull> queryf(int now, int l, int r, int L, int R) {
        if (L <= l && r <= R) return f[now];
        int mid = (l + r) >> 1;
        if (L > mid) return queryf(now << 1 | 1, mid + 1, r, L, R);
        if (mid >= R) return queryf(now << 1, l, mid, L, R);
        pair <ull, ull> re1 = queryf(now << 1, l, mid, L, R);
        pair <ull, ull> re2 = queryf(now << 1 | 1, mid + 1, r, L, R);
        return make_pair(re1.first * ds1[R - mid] + re2.first, re1.second * ds2[R - mid] + re2.second);
    }

    pair <ull, ull> queryg(int now, int l, int r, int L, int R) {
        if (L <= l && r <= R) return g[now];
        int mid = (l + r) >> 1;
        if (L > mid) return queryg(now << 1 | 1, mid + 1, r, L, R);
        if (mid >= R) return queryg(now << 1, l, mid, L, R);
        pair <ull, ull> re1 = queryg(now << 1, l, mid, L, R);
        pair <ull, ull> re2 = queryg(now << 1 | 1, mid + 1, r, L, R);
        return make_pair(re2.first * ds1[mid - L + 1] + re1.first, re2.second * ds2[mid - L + 1] + re1.second);
    }
}T;

pair <ull, ull> operator +(pair <ull, ull> a, pair <ull, ull> b) {
    return make_pair(a.first + b.first, a.second + b.second);
}

int main() {
    scanf("%d %d %d %d", &n, &q, &k, &b);
    for (int i = 1; i <= n; i++) scanf("%d", &a[i]), a[i] = 2 * a[i] - k * i;

    ds1[0] = 1; ds2[0] = 1;
    for (int i = 1; i <= n; i++) ds1[i] = ds1[i - 1] * di1;
    for (int i = 1; i <= n; i++) ds2[i] = ds2[i - 1] * di2;
    T.build(1, 1, n);

    while (q--) {
        int op; scanf("%d", &op);
        if (op == 1) {
            int l, r, v; scanf("%d %d %d", &l, &r, &v); v = v * 2;
            T.insert(1, 1, n, l, v);
            if (r < n) T.insert(1, 1, n, r + 1, -v);
        }
        if (op == 2) {
            int x; scanf("%d", &x);
            if (x == 1 || x == n) {printf("0\n"); continue;}
            if ((T.queryf(1, 1, n, x, x) + T.queryf(1, 1, n, x + 1, x + 1)) != make_pair((ull)2 * b, (ull)2 * b)) {printf("0\n"); continue;}
            int L = 2, R = min(n - x, x), re = 1;
            while (L <= R) {
                int mid = (L + R) >> 1;
                if ((T.queryg(1, 1, n, x - mid + 1, x - 1) + T.queryf(1, 1, n, x + 2, x + mid)) == make_pair(0llu, 0llu)) re = mid, L = mid + 1;
                    else R = mid - 1;
            }
            printf("%d\n", re);
        }
    }

    return 0;
}