#include <bits/stdc++.h>
using namespace std;
int main(){
	int n,m;
	cin>>n>>m;
	cout<<(m-n)*30;
	return 0;
}

/**************************************************************
	Problem: 1320
	User: zhouhongyi
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/