import java.util.*;
public class Main{
        public static void main(String[] args){
                Scanner sc = new Scanner(System.in);
                int a = sc.nextInt() % 12;
                int b = sc.nextInt();
                sc.close();
                double tyo = b * 6.0;
                double tan = (60 * a + b) / 2.0;
                double sa = tan - tyo;
                if(sa < 0) sa += 360;
                System.out.println((int)(sa / 5.5 * 60));
        }
}