#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <functional>
#include <set>
#include <sstream>
#include <map>
#include <queue>
#include <stack>

using namespace std;

const long long mod=1000000007; 

int main()
{

	long long a,b,c,d;
	cin>>a>>b>>c>>d;
	cout<<((((a%d)*(b%d))%d)*(c%d))%d<<endl;
	
	return 0;
}