#include <bits/stdc++.h>
#define st first
#define nd second
#define pb push_back
#define mp make_pair
#define ll long long
using namespace std;
ifstream fin( "inversmodular.in" );
ofstream fout( "inversmodular.out" );
void fast()
{
    cin.tie( 0 );
    ios_base::sync_with_stdio( 0 );
}
int a,b;
void invers( int a, int b, int &x, int &y )
{
    if( !b )
        {
            x = 1;
            y = 0;
            return;
        }

    int x0, y0;
    invers( b, a % b, x0, y0 );
    x = y0;
    y = x0 - y0 * ( a / b );
}
int main()
{
    fast();
    fin >> a >> b;
    int x, y;
    invers( a, b, x, y );

    while( x < 0 )
        x = ( x + b ) % b;

    fout << x;
    return 0;
}