Problem:
Score : 400 points

Problem Statement

Given are positive integers A and B.

Let us choose some number of positive common divisors of A and B.

Here, any two of the chosen divisors must be coprime.

At most, how many divisors can we choose?

Definition of common divisor

An integer d is said to be a common divisor of integers x and y when d divides both x and y.

Definition of being coprime

Integers x and y are said to be coprime when x and y have no positive common divisors other than 1.

Definition of dividing

An integer x is said to divide another integer y when there exists an integer \alpha such that y = \alpha x.

Constraints

All values in input are integers.

1 \leq A, B \leq 10^{12}

Input

Input is given from Standard Input in the following format:

A B

Output

Print the maximum number of divisors that can be chosen to satisfy the condition.

Sample Input 1

12 18

Sample Output 1

3

12 and 18 have the following positive common divisors: 1, 2, 3, and 6.

1 and 2 are coprime, 2 and 3 are coprime, and 3 and 1 are coprime, so we can choose 1, 2, and 3, which achieve the maximum result.

Sample Input 2

420 660

Sample Output 2

4

Sample Input 3

1 2019

Sample Output 3

1

1 and 2019 have no positive common divisors other than 1.

Solution in Rust (1.15.1) (judge verdict: Runtime Error)

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|s| s.parse().ok().unwrap())
        .collect()
}

fn gcd(a: usize, b: usize) -> usize {
    if a % b == 0 {
        b
    } else {
        gcd(b, a % b)
    }
}

fn sieve(n: usize) -> Vec<usize> {
    let mut primes = vec![];
    let mut is_prime = vec![true; n + 1];
    for i in 2..n+1 {
        if !is_prime[i] {
            continue;
        }
        primes.push(i);
        for j in i..n/i+1 {
            is_prime[i * j] = false;
        }
    }
    primes
}

fn count_factor(n: usize, primes: &[usize]) -> usize {
    let mut count = 0;

    for prime in primes.iter() {
        if n % prime != 0 {
            continue;
        }
        count += 1;
    }
    count
}

fn main() {
    let input = read_vec::<usize>();
    let (a, b) = (input[0], input[1]);

    let g = gcd(a,b);
    let primes = sieve(g);
    let count = count_factor(g, &primes);

    println!("{}", count+1);
}