fn mcd(mut a: i32, mut b: i32) -> i32
{
    while a % b != 0 {
        let t = a;

        a = b;
        b = t % a;
    }

    b
}

fn main()
{
    let a = 66;
    let b = 12;
    let m = mcd(a, b);

    println!("mcd({},{})={}", a, b, m);
}