#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
using i32 = int_fast32_t;
using i64 = int_fast64_t;
#define rep(i, n) for (i32 i = 0; i < (i32)(n); i++)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
using P = pair<i64,i64>;

int main(){
ios::sync_with_stdio(false);
std::cin.tie(nullptr);
i64 n,m,k;
cin >> n >> m >> k;
char op;
cin >> op;
vector<i64> b(m),a(n);
rep(i,m) cin >> b[i];
rep(i,n) cin >> a[i];
sort(all(a));
sort(all(b));
i64 ans = 0;
rep(i,n){
    if(op == '*'){
        auto itr = lower_bound(all(b),k / a[i]);
        ans += (b.end() - itr);
    }else{
        auto itr = lower_bound(all(b),k - a[i]);
        ans += (b.end() - itr);
    }
}
cout << ans << endl;
}