#include<iostream>
#include<string>
#include<algorithm>
#include<cmath>
#include<iomanip>
#include<cstring>
#include<map>
#include<vector>
#include<queue>
#include<climits>
using namespace std;
typedef long long int ll;

int main(){

	ll a, b, c, d, ans;
	cin >> a >> b >> c >> d;
	ans=(a*b)%(1000000007);
	ans*=c;
	ans%=1000000007;
	cout << ans%d << endl;
  
  return 0;
}