#include <bits/stdc++.h>
using namespace std;
int main(){
	int x,y,a,t;
	cin>>x>>y;
	a=y/x;
	t=a*5;
	cout<<t; 
}

/**************************************************************
	Problem: 1417
	User: wngjinming
	Language: C++
	Result: Accepted
	Time:12 ms
	Memory:2072 kb
****************************************************************/