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

}

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