#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using PII = std::pair<int, int>;
using PLL = std::pair<ll, ll>;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for (int i = (s); i < (int)(n); i++)

const int mod = 1e9 + 7;

ll cal(ll r, ll c, char op)
{
    if (op == '*')
        return r * c;
    if (op == '+')
        return r + c;
    return 0;
}

int main()
{

#ifdef DEBUG
    cout << "DEBUG MODE" << endl;
    ifstream in("input.txt"); //for debug
    cin.rdbuf(in.rdbuf());    //for debug
#endif

    ll h, w, k, x;
    int d;
    ll ans = 0;
    char op;
    
    cin >> h >> w >> k >> op;
    vector<ll> c(w), r(h);
    rep(i, w) cin >> c[i];
    rep(i, h) cin >> r[i];

    sort(c.begin(), c.end());
    rep(i, h)
    {
        if (op == '+')
            d = c.cend() -upper_bound(c.cbegin(), c.cend(), k - r[i]);
        if (op == '*')
            d = c.cend() -upper_bound(c.cbegin(), c.cend(), k / r[i]);
        ans += d;
        
    }
    
    cout << ans << endl;
    return 0;
}