use std::str::{FromStr, SplitWhitespace};
use std::fmt::Debug;

trait ReadExt {
    fn read<T: FromStr>(&mut self) -> T
    where
        <T as FromStr>::Err: Debug;
    fn read_vec<T: FromStr>(&mut self, n: usize) -> Vec<T>
    where
        <T as FromStr>::Err: Debug,
        T: Debug;
}
impl<'a> ReadExt for SplitWhitespace<'a> {
    fn read<T: FromStr>(&mut self) -> T
    where
        <T as FromStr>::Err: Debug,
    {
        if let Some(word) = self.next() {
            match word.parse::<T>() {
                Ok(res) => {
                    res
                }
                Err(e) => {
                    panic!("Failed to parse '{}' as requested type: {:?}", word, e);
                }
            }
        } else {
            panic!("Failed to read: No more words available for parsing.");
        }
    }
    fn read_vec<T: FromStr>(&mut self, n: usize) -> Vec<T>
    where
        <T as FromStr>::Err: Debug,
        T: Debug,
    {
        let mut vec = Vec::with_capacity(n);
        for _ in 0..n {
            let element = self.read::<T>();
            vec.push(element);
        }
        vec
    }
}

fn main() {
    let stdin = std::io::read_to_string(std::io::stdin()).unwrap();
    let mut stdin = stdin.split_whitespace();
    let n = stdin.read::<u128>();
    let b = stdin.read::<u128>();
    for i in 0..b{
        if (n*i)%b == 1 % b {
            println!("{:?}",i);
            return;
        }
    }
    println!("NaN");
}