#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
signed main() { 
  ios::sync_with_stdio(false); cin.tie(0);
  int n, m, k;
  cin >> n >> m >> k;
  char op;
  cin >> op;
  vector<int> b(m);
  for (int i = 0; i < m; i++) cin >> b[i];
  sort(b.begin(), b.end());
  long long ans = 0;
  for (int i = 0; i < n; i++) {
    int a;
    cin >> a;
    ans += m - (lower_bound(b.begin(), b.end(), (op == '*' ? (k + a - 1) / a : k - a)) - b.begin());
  }
  cout << ans << endl;
  return 0;
}