#include <bits/stdc++.h>
using namespace std;
static constexpr int Maxn = 2e5 + 5;
static constexpr uint64_t MOD1 = 1e9 + 7, MOD2 = 1e9 + 9, BA = 4.2e8;
static constexpr uint64_t BASE1 = 100037, BASE2 = 99983;
uint64_t pw1[Maxn], pw2[Maxn];
using hash_t = tuple<int, uint64_t, uint64_t>;
hash_t operator + (const hash_t &lhs, const hash_t &rhs) {
  int rl = get<0>(rhs), len = get<0>(lhs) + get<0>(rhs);
  uint64_t h1 = (get<1>(lhs) * pw1[rl] + get<1>(rhs)) % MOD1;
  uint64_t h2 = (get<2>(lhs) * pw2[rl] + get<2>(rhs)) % MOD2;
  return hash_t(len, h1, h2);
} // hash_t operator +
int n, qn, k, B;
int a[Maxn], b[Maxn], d[Maxn], fen[Maxn];
void upd(int x, int v) { for (; x <= n; x += x & -x) fen[x] += v; }
int ask(int x) { int r = 0; for (; x; x -= x & -x) r += fen[x]; return r; }
hash_t hl[Maxn << 2], hr[Maxn << 2];
#define ls (p << 1)
#define rs (p << 1 | 1)
void pushup(int p) {
  hl[p] = hl[ls] + hl[rs];
  hr[p] = hr[rs] + hr[ls];
} // pushup
pair<hash_t, hash_t> query(int p, int l, int r, int L, int R) {
  if (L == l && r == R) return pair(hl[p], hr[p]);
  int mid = (l + r) >> 1;
  if (R <= mid) return query(ls, l, mid, L, R);
  if (L > mid) return query(rs, mid + 1, r, L, R);
  auto ll = query(ls, l, mid, L, mid);
  auto rr = query(rs, mid + 1, r, mid + 1, R);
  return pair(ll.first + rr.first, rr.second + ll.second);
} // query
void update(int p, int l, int r, int x, int v) {
  if (l == r) {
    hl[p] = hash_t(1, v + BA, v + BA);
    hr[p] = hash_t(1, -v + BA, -v + BA);
  } else {
    int mid = (l + r) >> 1;
    if (x <= mid) update(ls, l, mid, x, v);
    else update(rs, mid + 1, r, x, v);
    pushup(p);
  }
} // update
void print(int p, int l, int r) {
  if (l == r) {
    fprintf(stderr, "%d, ", get<1>(hl[p]) - BA);
  } else {
    int mid = (l + r) >> 1;
    print(ls, l, mid);
    print(rs, mid + 1, r);
  }
} // print
int main(void) {
  ios_base::sync_with_stdio(false);
  cin >> n >> qn >> k >> B;
  for (int i = 1; i <= n; ++i) cin >> a[i], b[i] = 2 * a[i] - k * i;
  for (int i = 1; i <= n; ++i) d[i] = b[i] - b[i - 1];
  for (int i = 1; i <= n; ++i) upd(i, a[i] - a[i - 1]);
  for (int i = 1; i <= n; ++i) update(1, 1, n, i, d[i]);
  // for (int i = 1; i <= n; ++i) fprintf(stderr, "%d, ", b[i]); fprintf(stderr, "\n");
  // for (int i = 1; i <= n; ++i) fprintf(stderr, "%d, ", d[i]); fprintf(stderr, "\n");
  while (qn--) {
    int op, l, r, v;
    cin >> op >> l;
    // fprintf(stderr, "-------------------------------- (%d, %d\n", op, l);
    if (op == 1) {
      cin >> r >> v;
      upd(l, v), upd(r + 1, -v);
      d[l] += 2 * v, d[r + 1] -= 2 * v;
      update(1, 1, n, l, d[l]);
      if (r + 1 <= n) update(1, 1, n, r + 1, d[r + 1]);
    } else {
      if (l == 1 || l == n) { cout << "0\n"; continue; }
      int al = ask(l - 1), ar = ask(l + 1);
      if (ar - al != k + B) { cout << "0\n"; continue; }
      int low = 1, high = min(l - 2, n - l - 1), res = 0;
      // fprintf(stderr, "(%d, %d)\n", low, high);
      auto check = [&](int len)->bool {
        int l1 = l - len, r1 = l - 1;
        int l2 = l + 2, r2 = l + len + 1;
        // fprintf(stderr, "(%d, %d), (%d, %d)\n", l1, r1, l2, r2);
        auto a1 = query(1, 1, n, l1, r1);
        auto a2 = query(1, 1, n, l2, r2);
        // fprintf(stderr, "a1 = (%d, %d, %d)\n", get<0>(a1.first), get<1>(a1.first) - BA, get<2>(a1.first) - BA);
        // fprintf(stderr, "a2 = (%d, %d, %d)\n", get<0>(a2.second), get<1>(a2.second) - BA, get<2>(a2.second) - BA);
        return a1.first == a2.second;
      };
      while (low <= high) {
        int mid = (low + high) >> 1;
        if (check(mid)) low = mid + 1, res = mid;
        else high = mid - 1;
      }
      cout << 1 + res << endl;
    }
    // print(1, 1, n);
  }
  return 0;
} // main