#include<bits/stdc++.h>
using namespace std;
int main(){
	float a,b,c;
	cin>>a>>b;
	c=b/a*5;
	cout<<c;
}
/**************************************************************
	Problem: 1417
	User: sucongyi
	Language: C++
	Result: Accepted
	Time:12 ms
	Memory:2072 kb
****************************************************************/