#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

//INSERT ABOVE HERE
signed main(){
  Int n,m,k;
  cin>>n>>m>>k;
  char op;
  cin>>op;
  vector<Int> as(n),bs(m);
  for(Int i=0;i<m;i++) cin>>bs[i];
  for(Int i=0;i<n;i++) cin>>as[i];

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

  Int ans=0;
  for(Int b:bs){
    if(op=='+') ans+=as.end()-lower_bound(as.begin(),as.end(),k-b);
    if(op=='*') ans+=as.end()-lower_bound(as.begin(),as.end(),(k+b-1)/b);
  }
  cout<<ans<<endl;
  return 0;
}