#include <iostream>
#include <fstream>
using namespace std;

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

int a, n, k, l;

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

int main()
{
    f>>a;
    f>>n;
    euclid(a,n,k,l);
    if(k>=0)
        g<<k;
    else
        g<<k+n;
    return 0;
}