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

/**************************************************************
	Problem: 1320
	User: zhengzihao3
	Language: C++
	Result: Accepted
	Time:15 ms
	Memory:2072 kb
****************************************************************/