#include <iostream>
#include <string>
#include <cstring>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <vector>
#include <cmath>
#include <cstdlib>
#include <queue>
#include <stack>
#include <iomanip>
#include <fstream>
#include <unordered_set>

using namespace std;

#define REP(i, n) for(ll i = 0;i < n;i++)
#define REPR(i, n) for(ll i = n;i >= 0;i--)
#define FOR(i, m, n) for(ll i = m;i < n;i++)
#define FORR(i, m, n) for(ll i = m;i >= n;i--)
#define REPO(i, n) for(ll i = 1;i <= n;i++)
#define ll long long
#define INF (ll)1 << 60
#define MINF (-1 * INF)
#define ALL(n) n.begin(),n.end()
#define MOD 1000000007
#define P pair<ll, ll>


ll n, m, k, as, bs;
char c;
int main() {
	cin >> n >> m >> k >> c;
	vector<ll> a(n), b(m);
	REP(i, m) {
		cin >> b[i];
		bs += b[i];
	}
	REP(i, n) {
		cin >> a[i];
		as += a[i];
	}
	sort(ALL(a));
	a.push_back(INF);
	ll ans = 0;
	REP(i, m) {
		ll now;
		if (c == '+') now = k - b[i];
		else now = (k + b[i] - 1) / b[i];
		ll it = a.end() - lower_bound(ALL(a), now) - 1;
		//cout << it <<endl;
		ans += it;
	}
	cout << ans << endl;
}