#include <algorithm>
using namespace std;

long long a,n,inv,ins;

long long euclid_extins (long long &x,long long &y,long long a,long long b)
{
    long long aux;

    if (!b)
    {
        x=1;
        y=0;
    }
    else
    {
        euclid_extins (x,y,b,a%b);
        aux=x;
        x=y;
        y=aux-y*(a/b);
    }
}

int main ()
{
    freopen ("inversmodular.in","r",stdin);
    freopen ("inversmodular.out","w",stdout);

    scanf ("%lld%lld",&a,&n);
    euclid_extins (inv,ins,a,n);
    if (inv<=0)
        inv=n+inv%n;
    printf ("%lld",inv);

    return 0;
}