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)

use std::cmp::min;

fn read<T: std::str::FromStr>(
    stdin_lock: &mut std::io::StdinLock,
    buf: &mut Vec<u8>,
    delimiter: u8,
) -> T {
    buf.clear();
    let l = std::io::BufRead::read_until(stdin_lock, delimiter, buf).unwrap();
    buf.truncate(l - 1); // remove delimiter
    let s = unsafe { std::str::from_utf8_unchecked(&buf) };
    s.parse().unwrap_or_else(|_| panic!("read"))
}

fn gcd(a: i64, b: i64) -> i64 {
    fn gcd1(m: i64, n: i64) -> i64 {
        if n == 0 {
            m
        } else {
            gcd1(n, m % n)
        }
    }
    if a > b {
        gcd1(a, b)
    } else {
        gcd1(b, a)
    }
}

fn main() {
    let stdin = std::io::stdin();
    let mut stdin_lock = stdin.lock();
    let mut buf: Vec<u8> = Vec::new();
    let a: i64 = read(&mut stdin_lock, &mut buf, b' ');
    let b: i64 = read(&mut stdin_lock, &mut buf, b'\n');

    let m = gcd(a, b) as usize;
    let mut nv = vec![0i64; m + 1];
    for i in 2..m + 1 {
        nv[i] = i as i64;
    }
    let n = (min(a, b) as f64).sqrt() as usize;
    for i in 2..n {
        if nv[i] == 0 {
            continue;
        }
        let mut j = i + i;
        while j < m + 1 {
            nv[j] = 0;
            j += i;
        }
    }
    let mut ans = 1;
    for i in 0..m + 1 {
        let p = nv[i];
        if p != 0 && a % p == 0 && b % p == 0 {
            ans += 1;
        }
    }
    println!("{}", ans);
}