#include<bits/stdc++.h>
using namespace std;
int main(){
	
	int x,y,i,n;
	cin>>x>>y;
	i=y/x;
	n=i*5;
	cout<<n;
	
	return 0;
}
/**************************************************************
	Problem: 1417
	User: huangyaojie3
	Language: C++
	Result: Accepted
	Time:15 ms
	Memory:2072 kb
****************************************************************/