/* 
 * File:   main.cpp
 * Author: VirtualDemon
 *
 * Created on April 9, 2010, 4:01 PM
 */
#include <cstdlib>
#include <fstream>

/*
 * 
 */
using namespace std;
inline void gcd( int a, int b, int& x, int& y )
{
    if( !b )
    {
        x=1;
        y=0;
        return;
    }
    int x0, y0;
    gcd( b, a%b, x0, y0 );
    x=y0;
    y=x0-(a/b)*y0;
}
int main(int argc, char** argv)
{
    int A, N, x, y;
    ifstream in( "inversmodular.in" );
    ofstream out( "inversmodular.out" );
    in>>A>>N;
    gcd( A, N, x, y );
    x=( 0LL+N+x%N )%N;
    out<<x<<'\n';
    return EXIT_SUCCESS;
}