#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
using ll = long long;
using vi = vector<int>;

#define rep(i,n) for(int i=0;i<(n);++i)
#define all(f,c,...) (([&](decltype((c)) cccc) { return (f)(begin(cccc), end(cccc), ## __VA_ARGS__); })(c))


int main() {
  int N, M, K; cin >> N >> M >> K;
  char op; cin >> op;

  vi B(M);
  rep(i, M) cin >> B[i];
  all(sort, B);

  ll ans = 0;
  rep(i, N) {
    int A; cin >> A;
    ans += B.end() - all(lower_bound, B, (op == '+' ? K - A : (K+A-1) / A));
  }
  cout << ans << endl;


  return 0;
}