import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		int a = Integer.parseInt(sa[0]);
		int b = Integer.parseInt(sa[1]);
		br.close();

		a %= 12;
		int x = 60 * 60 * 12;
		int[] y = new int[12];
		for (int i = 0; i < 12; i++) {
			y[i] = x * i / 11;
		}

		int ans = Integer.MAX_VALUE;
		int t = 3600 * a + 60 * b;
		for (int i = 0; i < 12; i++) {
			int d = y[i] - t;
			if (d >= 0) {
				ans = Math.min(ans, d);
			}
		}
		System.out.println(ans);
	}
}