#include<bits/stdc++.h>
using namespace std;
int x,y,d;
int main(){
	cin>>x>>y;
	d=y/x;
	cout<<d*5;
	return 0;
}

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