lab2 

#include <iostream>
#include <cmath>
using namespace std;

int main(){

	double q, w, r, F, g;
	cin >> q >> w >> r >> g;
	if (pow(r,2) == 0)
	{
		cout << "no solutions";
	}
	else
	{
		
		F = g*((q*w) / pow(r,2));
		cout << F;
	}

	return 0;
}