1085 문제

#include <iostream>
#include<stdio.h>
using namespace std;

//1085
int main() {
	
	int h,b, c,s;

	double r =0;

	cin >> h>>b>>c>>s ;
	r = h * b * s * c;
	r = r / 8 / 1024 / 1024;
	cout << r;
	
	return 0;
}