#include <bits/stdc++.h>
#define pb emplace_back
#define fst first
#define scd second
#define mkp make_pair
#define mems(a, x) memset((a), (x), sizeof(a))

using namespace std;
typedef long long ll;
typedef double db;
typedef unsigned long long ull;
typedef long double ldb;
typedef pair<ll, ll> pii;

const int maxn = 200100;
const ll base = 131, mod1 = 998244853, mod2 = 1004535809;

ll n, m, K, B, a[maxn], b[maxn], c[maxn], pw1[maxn], pw2[maxn];

struct node {
	ll h1, h2, len;
};

inline node operator + (const node &a, const node &b) {
	node res;
	res.h1 = (a.h1 * pw1[b.len] + b.h1) % mod1;
	res.h2 = (a.h2 * pw2[b.len] + b.h2) % mod2;
	res.len = a.len + b.len;
	return res;
}

struct SGT {
	node a[maxn << 2];
	
	inline void pushup(int x) {
		a[x] = a[x << 1] + a[x << 1 | 1];
	}
	
	void build(int rt, int l, int r, ll *c) {
		if (l == r) {
			a[rt].h1 = a[rt].h2 = c[l];
			a[rt].len = 1;
			return;
		}
		int mid = (l + r) >> 1;
		build(rt << 1, l, mid, c);
		build(rt << 1 | 1, mid + 1, r, c);
		pushup(rt);
	}
	
	void update(int rt, int l, int r, int x, ll y) {
		if (l == r) {
			a[rt].h1 = a[rt].h2 = y;
			return;
		}
		int mid = (l + r) >> 1;
		(x <= mid) ? update(rt << 1, l, mid, x, y) : update(rt << 1 | 1, mid + 1, r, x, y);
		pushup(rt);
	}
	
	node query(int rt, int l, int r, int ql, int qr) {
		if (ql <= l && r <= qr) {
			return a[rt];
		}
		int mid = (l + r) >> 1;
		if (qr <= mid) {
			return query(rt << 1, l, mid, ql, qr);
		} else if (ql > mid) {
			return query(rt << 1 | 1, mid + 1, r, ql, qr);
		} else {
			return query(rt << 1, l, mid, ql, qr) + query(rt << 1 | 1, mid + 1, r, ql, qr);
		}
	}
} t1, t2;

void solve() {
	scanf("%lld%lld%lld%lld", &n, &m, &K, &B);
	pw1[0] = pw2[0] = 1;
	for (int i = 1; i <= n; ++i) {
		scanf("%lld", &a[i]);
		pw1[i] = pw1[i - 1] * base % mod1;
		pw2[i] = pw2[i - 1] * base % mod2;
	}
	for (int i = 1; i < n; ++i) {
		b[i] = a[i + 1] - a[i];
		c[n - i] = K - b[i];
	}
	t1.build(1, 1, n, b);
	t2.build(1, 1, n, c);
	while (m--) {
		ll op, x, y, z;
		scanf("%lld%lld", &op, &x);
		if (op == 1) {
			scanf("%lld%lld", &y, &z);
			if (x > 1) {
				b[x - 1] += z;
				t1.update(1, 1, n, x - 1, b[x - 1]);
				t2.update(1, 1, n, n - (x - 1), K - b[x - 1]);
			}
			if (y < n) {
				b[y] -= z;
				t1.update(1, 1, n, y, b[y]);
				t2.update(1, 1, n, n - y, K - b[y]);
			}
		} else {
			if (x == 1 || x == n) {
				puts("0");
				continue;
			}
			if (b[x - 1] + b[x] != K + B) {
				puts("0");
				continue;
			}
			// for (int i = 1; i < n; ++i) {
				// printf("%lld%c", b[i], " \n"[i == n - 1]);
			// }
			ll l = 1, r = min(x - 2, n - 1 - x), ans = 0;
			while (l <= r) {
				ll mid = (l + r) >> 1;
				node u = t1.query(1, 1, n, x - 1 - mid, x - 2), v = t2.query(1, 1, n, n - (x + mid), n - (x + 1));
				if (u.h1 == v.h1 && u.h2 == v.h2) {
					ans = mid;
					l = mid + 1;
				} else {
					r = mid - 1;
				}
			}
			printf("%lld\n", ans + 1);
		}
	}
}

int main() {
	int T = 1;
	// scanf("%d", &T);
	while (T--) {
		solve();
	}
	return 0;
}