#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n);i++)
#define sz(x) int(x.size())
typedef long long ll;
typedef pair<int,int> P;

int main(){
  int n, m, k;
  cin >> n >> m >> k;
  char op;
  cin >> op;
  vector<int> a(n), b(m);
  rep(i,m) cin >> b[i];
  rep(i,n) cin >> a[i];
  sort(b.begin(), b.end());
  ll res = 0;
  for (int i = 0; i < n; i++) {
    int x = (op == '+' ? k - a[i] : (k + a[i] - 1) / a[i]);
    auto cnt = lower_bound(b.begin(), b.end(), x) - b.begin();
    res += (m - cnt);
  }
  cout << res << endl;
  return 0;
}