macro_rules! read_line_to_tuple {
    ( $( $t:ty ),* ) => {{
        let mut input = String::new();
        std::io::stdin().read_line(&mut input).unwrap();
        let mut iter = input.split_whitespace();
        ( $( iter.next().unwrap().parse::<$t>().unwrap() ),* )
    }};
}

fn main() {
    let (a, b) = read_line_to_tuple!(i32, i32);

    let long_hand = a * 60 + b;
    let short_hand = b * 12;

    let mut diff = (long_hand - short_hand) % 720;
    if diff < 0 {
        diff += 720;
    }

    let ans = diff * 60 / 11;
    println!("{}", ans);
}