#include <cstdio>

using namespace std;
long long a,n,x0,x1,r,c,x,aux;

int main()
{
    freopen("inversmodular.in","r",stdin);
    freopen("inversmodular.out","w",stdout);
    scanf("%lld%lld",&a,&n);
    aux=n;
    x0=0;
    x1=1;
    while(a!=0)
    {
        r=n%a;
        c=n/a;
        n=a;
        a=r;
        x=x0-x1*c;
        x0=x1;
        x1=x;
    }
    if(x0<=0)
      x0=aux+x0%aux;
    printf("%lld\n",x0);
    return 0;
}