#include <stdio.h>

#define ll long long

int A, N;

inline ll gcd(int a, int b) {
    return !b ? a : gcd(b, a % b);
}

int main() {
    ll inv = 0, ins;
    freopen("inversmodular.in", "r", stdin);
    freopen("inversmodular.out", "w", stdout);
    scanf("%d %d", &A, &N);
    inv = gcd(A, N);
    if (inv <= 0)
        inv = N + inv % N;
    printf("%lld\n", inv);
    return 0;
}