#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: wangyiyang
	Language: C
	Result: Compile Error
****************************************************************/