#include<iostream>
#include <array>
#include<string>
using namespace std;






int main(){
	
	array<int, 4> Intezer;
	for (int i = 0; i < 4; i++){
		cin >> Intezer[i];
	}
	cout << Intezer[0] * Intezer[1] * Intezer[2] % Intezer[3]<<endl;
	system("pause");
	return 0;
}