#include <bits/stdc++.h>

using namespace std;

#define int long long

const int N = 200'000 + 10;
int n, q, k, b;

int f[N << 2], lazy[N << 2];
inline void push(int s, int l, int r) { 
  int mid = (l + r) >> 1;
  f[s << 1] += (mid - l + 1) * lazy[s];   f[s << 1 | 1] += (r - mid) * lazy[s];
  lazy[s << 1] += lazy[s];                lazy[s << 1 | 1] += lazy[s];
  lazy[s] = 0;
}

void update(int s, int l, int r, int u, int v, int x) { 
  if (v < l || u > r) return;
  if (u <= l && r <= v) { 
    f[s] += (r - l + 1) * x;
    lazy[s] += x;
    return;
  }
  push(s, l, r);
  int mid = (l + r) >> 1;
  update(s << 1, l, mid, u, v, x);  update(s << 1 | 1, mid + 1, r, u, v, x);
  f[s] = f[s << 1] + f[s << 1 | 1];
}
int query(int s, int l, int r, int u, int v) { 
  if (v < l || u > r) return 0;
  if (u <= l && r <= v) return f[s];
  push(s, l, r);
  int mid = (l + r) >> 1;
  return query(s << 1, l, mid, u, v) + query(s << 1 | 1, mid + 1, r, u, v);
}

int32_t main() { 
  cin.tie(0)->sync_with_stdio(0);

  cin >> n >> q >> k >> b;
  for (int i = 1; i <= n; ++i) { 
    int x; cin >> x;
    update(1, 1, n, i, i, x);
  }

  while (q--) { 
    int type; cin >> type;

    if (type == 1) { 
      int l, r, x; cin >> l >> r >> x;
      update(1, 1, n, l, r, x);
    } else { 
      int i; cin >> i;

      int l = 1, r = min(i - 1, n - i), ret = 0;
      while (l <= r) { 
        int mid = (l + r) >> 1;

        int value = k * (mid + 1) * mid / 2 + b * mid;
        if (query(1, 1, n, i + 1, i + mid) - query(1, 1, n, i - mid, i - 1) 
            == value) l = (ret = mid) + 1;
        else r = mid - 1;
      }

      cout << ret << "\n";
    }
  }
}