#include <cstdio>
using namespace std;

long long gcd(long long a, long long b, long long &x, long long &y) {
    if (!b) {
        x = 1;
        y = 0;
        return a;
    }
    long long x0, y0, d = gcd(b, a % b, x0, y0);
    x = y0;
    y = x0 - (a/b) * y0;
    return d;
}

long long invers(long long A, long long N) {
    long long inv, x;
    gcd(A, N, inv, x);

    while (inv <= 0) inv += N;

    return inv;
}

int main() {
    freopen("inversmodular.in", "r", stdin );
    freopen("inversmodular.out", "w", stdout);

    long long A, N;
    scanf("%lld%lld", &A, &N);
    printf("%lld\n", invers(A, N));

    return 0;
}