#include <iostream>
#include <cstdio>
using namespace std;
void euclid( long a, long b, long &x, long &y)
{
    if(b==0)
    {
        x=1;
        y=0;
    }
    else
    {
    long x0=0, y0=0;
    euclid(b, a%b, x0, y0);
    x=y0;
    y=x0- (a/b) * y0;
    }
}
int main()
{
    freopen ("inversmodular.in", "r", stdin);
    freopen ( "inversmodular.out", "w", stdout);

    long A,N,X,Y;
    cin>>A>>N;
    euclid(A,N,X,Y);
    while(X<0)
        X+=N;
    cout<<X;
    return 0;
}