#include <bits/stdc++.h>
using namespace std;
const int N = 100010;
int dp[N][310], c[N][310], lst[N], a[N], b[N];
vector<int> v[N];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n, m, s, e;
  cin >> n >> m >> s >> e;
  for (int i = 0; i < n; i++) {
    cin >> a[i + 1];
  }
  for (int i = 0; i < m; i++) {
    cin >> b[i + 1];
    v[b[i + 1]].push_back(i + 1);
  }
  for (int i = 0; i <= n; i++) {
    for (int j = 0; j <= 300; j++) {
      dp[i][j] = -1;
    }
    lst[i] = -1;
  }
  lst[0] = 0;
  for (int i = 1; i <= n; i++) {
    for (int j = min(300, n); j >= 1; j--) {
      if (lst[j - 1] == -1 || v[a[i]].size() == 0) continue;
      if (v[a[i]].back() <= lst[j - 1]) continue;
      int ind = upper_bound(v[a[i]].begin(), v[a[i]].end(), lst[j - 1]) -
                v[a[i]].begin();
      dp[i][j] = v[a[i]][ind];
      c[i][j] = e * j + dp[i][j] + i;
      if (lst[j] == -1)
        lst[j] = v[a[i]][ind];
      else
        lst[j] = min(v[a[i]][ind], lst[j]);
    }
  }
  int ans = n;
  for (int i = n; i >= 0; i--) {
    if (lst[i] != -1) {
      ans = i;
      break;
    }
  }
  for (int j = ans; j >= 1; j--) {
    int k = 1000000000;
    for (int i = 1; i <= n; i++) {
      if (dp[i][j] != -1) {
        k = min(k, c[i][j]);
      }
    }
    if (k <= s) {
      cout << j;
      return 0;
    }
  }
  cout << 0;
}
