#include <iostream>
using namespace std;

int main() {
    int m, n;
    cin >> m >> n;
    int degree = (n - m) * 30;
    cout << degree << endl;
    return 0;
}

/**************************************************************
	Problem: 1320
	User: fuyijun
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/