#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long ll;

int main() {
  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(), greater<int>());

  ll ans = 0;
  for (int i = 0; i < n; i++) {
    int a; cin >> a;
    int x = op == '+' ? max(0, k-a) : (k + a - 1) / a;
    int l = 0, r = m;
    while(l < r) {
      int c = (l + r) / 2;
      if (x > b[c])
        r = c;
      else
        l = c + 1;
    }
    ans += l;
  }
  cout << ans << endl;
}