#include<bits/stdc++.h>
   
using namespace std;
  
#define rep(i,n) for(int i=0;i<(n);++i)
#define reps(i,n) for(int i=1;i<=(n);++i)
#define all(x) (x).begin(),(x).end()
#define Fixed fixed << setprecision(14)
#define int int64_t
using pii = pair<int,int>;
constexpr int INF  = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr int mod1 = 1e9+7; 
constexpr int mod2 = 998244353;
 
template <class A, class B> inline bool chmax(A &a, const B &b) { return b > a && (a = b, true); }
template <class A, class B> inline bool chmin(A &a, const B &b) { return b < a && (a = b, true); }
 
template <class T> using min_heap = priority_queue<T,vector<T>,greater<T> >;
template <class T> using max_heap = priority_queue<T>;
template <class A,class B> using umap = unordered_map<A,B>;
   
int gcd(int a,int b){ return b ? gcd(b,a % b) : a;}
int lcm(int a,int b){ return a / gcd(a,b) * b;}

signed main(void){
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);

  int n,m,k;
  char op;
  cin >> n >> m >> k >> op;

  vector<int> b(m),a(n);

  rep(i,m){
    cin >> b[i];
  }
  rep(i,n){
    cin >> a[i];
  }

  sort(all(b),greater<int>());

  auto BinarySearch = [&](int key){
    int ok = -1,ng = m;
    while(ng - ok > 1){
      int mid = (ng + ok) / 2;
      if(op == '+'){
        if(b[mid] + key >= k) ok = mid;
        else ng = mid;
      }else{
        if(b[mid] * key >= k) ok = mid;
        else ng = mid;
      }
    }
    return ok + 1;
  };

  int res = 0;
  rep(i,n){
    res += BinarySearch(a[i]);
  }

  cout << res << '\n';

  return 0;
}