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

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