#include <fstream>

using namespace std;

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

void euclid_extins(int a, int b, int &x, int &y, int &d)
{
    if (b == 0)
    {
        d = a;
        x = 1;
        y = 0;
        return;
    }
    int xx, yy, q = a / b;
    euclid_extins(b, a % b, xx, yy, d);
    x = yy;
    y = xx - yy * q;
}

int main()
{
    int a, n;
    int x, y, d;
    in >> a >> n;
    euclid_extins(a, n, x, y, d);
    out << (n + x%n) % n;
    in.close();
    out.close();
    return 0;
}