#include <iostream>
#include <fstream>

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

void euclid(int a, int b, int &c, int &x, int &y)
{
    if(b == 0){
        c = a;
        x = 1;
        y = 0;
    }
    else{
        int x0, y0;
        euclid(b, a%b, c, x0, y0);
        x = y0;
        y = x0 - (a/b)*y0;
    }
}

int main()
{
    int a, n, c, x, y;
    fin >> a >> n;
    euclid(a, n, c, x, y);

    while(x < 0) x += n;

    fout << x;

    return 0;
}