fn gcd(n: i64, m: i64) -> i64 {
    if n % m == 0 { m } else { gcd(m, n % m) }
}

fn remove_common_prime_divisors(mut n: i64, m: i64) -> i64 {
    while n != 1 {
        let d = gcd(n, m);
        if d == 1 {
            break;
        }
        n /= d;
    }

    n
}

fn common_prime_divisors(a: &[i64], b: &[i64]) -> i64 {
    let mut counter = 0;
    for i in 0..a.len() {
        let x = a[i];
        let y = b[i];
        let d = gcd(x, y);

        let x = remove_common_prime_divisors(x, d);
        if x != 1 {
            continue;
        }

        let y = remove_common_prime_divisors(y, d);
        if y == 1 {
            counter += 1;
        }
    }

    counter
}