#![allow(non_snake_case)]

use std::io::{ self, prelude::* };

macro_rules! pick {
    ($tokens:expr) => {
        $tokens.next().unwrap().parse().expect("parse error")
    }
}

fn main() {
    let mut s = String::new();
    io::stdin().read_to_string(&mut s).expect("i/o error");
    let mut tokens = s.split_whitespace();

    let A: i64 = pick!(tokens);
    let B: i64 = pick!(tokens);

    for m in 1.. {
        let a_min = m*(10*A-5) / 1000;
        let a_max = m*(10*A+5) / 1000;
        for a in a_min..=a_max {
            let b = m - a;
            if m*(10*A-5) <= 1000*a && 1000*a < m*(10*A+5) &&
               m*(10*B-5) <= 1000*b && 1000*b < m*(10*B+5) {
                println!("{}", m);
                return;
            }
        }
    }
}