#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<map>
#include<set>
#include<cstdio>
#include<cmath>
#include<deque>
#include<numeric>
#include<queue>
#include<stack>
#include<cstring>
#include<limits>
#include<functional>
#include<unordered_set>
#include<iomanip>
#include<cassert>
#include<regex>
#include<bitset>
#include<complex>
#include<chrono>
#define rep(i,a) for(int i=(int)0;i<(int)a;++i)
#define pb push_back
#define eb emplace_back
using ll=long long;
constexpr ll mod = 1e9 + 7;
constexpr ll INF = 1LL << 60;
 
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
 
using namespace std;
//ここから
void solve(){
  ll n,m,k;
  cin>>n>>m>>k;
  char op;
  cin>>op;
  vector<ll>b(m),a(n);
  rep(i,m)cin>>b[i];
  rep(i,n)cin>>a[i];
  sort(a.begin(),a.end());
  sort(b.begin(),b.end());
  ll ans=0;
  if(op=='+'){
    rep(i,n){
      ll x=k-a[i];
      int pos=b.end()-lower_bound(b.begin(),b.end(),x);
      ans+=pos;
    }
  }
  else {
    rep(i,n){
      ll x=(k+a[i]-1)/a[i];
      int pos=b.end()-lower_bound(b.begin(),b.end(),x);
      ans+=pos;
    }
  }
  cout<<ans<<"\n";
}

int main(){
	ios::sync_with_stdio(false);
  cin.tie(0);
	cout<<fixed<<setprecision(15);
	solve();
	return 0;
}