#include <iostream>
#include <fstream>

using namespace std;

ifstream fin ("inversmodular.in");
ofstream fout ("inversmodular.out");

void euclid(long long  a, long long b, long long &x, long long &y) {
    if(b == 0)
        x = 1, y = 0;
    else {
        long long x1, y1;
        euclid(b, a % b, x1, y1);
        x = y1;
        y = x1 - (a/b) * y1;
    }
}

int main() {
    long long a, n; fin >> a >> n;
    long long x, y;
    euclid(a, n, x, y);
    while(x < 0)
        x += n;
    fout << x;

}