using System;

public class Hello
{
    static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var a = int.Parse(line[0]);
        var b = int.Parse(line[1]);
        getAns(a, b);
    }
    static void getAns(int a, int b)
    {
        var L = b * 6d;
        var s = 30 * a + b / 2d;
        if (s >= 360d) s -= 360d;
        if (L <= s) { Console.WriteLine((int)(120d * (s - L) / 11d)); return; }
        var k = 360d - 6d * b + s;
        Console.WriteLine((int)(120d * k / 11d));
    }
}