#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <cmath>
#include <iomanip>
#include <stack>
#include <queue>
#include <numeric>
#include <map>
#include <unordered_map>
#include <set>
#include <fstream>
#include <chrono>
#include <random>
#include <bitset>
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) ((int)(x).size())
#define pb push_back
#define mod 1000000007
using ll = long long;
using namespace std;
ll gcd(ll a, ll b) {return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) {return a/gcd(a,b)*b;}

ll N, M, K;
char op;
vector<ll> A;
vector<ll> B;

ll calc(ll a, ll b){
  if(op == '+') return a+b;
  else return a*b;
}

bool isok(ll x, ll a){
  // code here
  if(calc(a,B[x])>=K) return true;
  else return false;
}
ll binsch(ll a){
  // set value
  ll ng = -1; ll ok = M;
  while(abs(ok-ng)>1){
    ll mid = (ok+ng)/2;
    if(isok(mid, a)) ok = mid;
    else ng = mid;
  }
  return ok;
}

int main(){
  cin >> N >> M >> K;
  cin >> op;
  A.resize(N); B.resize(M);
  rep(i,M) cin >> B[i];
  rep(i,N) cin >> A[i];
  sort(all(A));
  sort(all(B));
  ll ans = 0;
  rep(i,N){
    ans += binsch(A[i]);
  }
  cout << N*M-ans << endl;
  return 0;
}