#include <iostream>

using namespace std;

long long gcd(long long a, long long b, long long &x, long long &y) {
    if (b == 0) {
        x = 1;
        y = 0;
        return a;
    }
    long long x1, y1;
    long long g = gcd(b, a % b, x1, y1);
    x = y1;
    y = x1 - (a / b) * y1;
    return g;
}

int main() {
    long long a, n;
    cin >> a >> n;

    long long x, y;
    gcd(a, n, x, y);

    long long inv = (x % n + n) % n;

    cout << inv;
    return 0;
}