#include <bits/stdc++.h>

using ll = long long;

using namespace std;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    ll n, m, k;
    string op;
    cin >> n >> m >> k >> op;

    vector<ll> va(n), vb(m);

    for (int i = 0; i < m; ++i)
        cin >> vb[i];
    for (int i = 0; i < n; ++i)
        cin >> va[i];

    sort(va.begin(), va.end());

    ll res{ 0 };
    if (op == "+")
    {
        for (int i = 0; i < m; ++i)
        {
            vector<ll>::iterator it = lower_bound(va.begin(), va.end(), k - vb[i]);
            res += distance(it, va.end());
        }
    }
    else
    {
        for (int i = 0; i < m; ++i)
        {
            vector<ll>::iterator it = lower_bound(va.begin(), va.end(), (k + vb[i] - 1) / vb[i]);
            res += distance(it, va.end());
        }
    }

    cout << res << "\n";

    return 0;
}