#include <iostream>
using namespace std;
 
int main() {
    int m, n;
    cin >> m >> n;  // 读取起始时间和结束时间 
    
    int degrees = (n - m) * 30;  // 计算旋转角度 
    
    cout << degrees << endl;
    
    return 0;
}
/**************************************************************
	Problem: 1320
	User: linmiaoling
	Language: C++
	Result: Accepted
	Time:6 ms
	Memory:2072 kb
****************************************************************/