#include <fstream>
#include <cstdio>
using namespace std;

ofstream g("inversmodular.out");
long a,b,c,r,cat,n,aux,i,j,x,y,ok,xa,ya;

long modul(long k)
{
    if (k<0)
        return -k;
    return k;
}
long cmmdc(long a,long b)
{
    long r=1;
    while (r!=0)
    {
        r=a%b;
        a=b;
        b=r;
    }
    return a;
}
int main()
{
    freopen("inversmodular.in","r",stdin);
    scanf("%ld%ld",&x,&y);
    a=x;
    b=-y;
    c=1;
    if (b>a)
    {
        aux=a;
        a=b;
        b=aux;
        ok=1;
    }
    if (b==0)
    {
        if (c%a==0)
            g<<c/a<<'\n';
        else
            g<<"0\n";
    }
    else if (c%cmmdc(modul(a),modul(b))==0)
    {
        xa=1;ya=0;x=0;y=1;

        while (b)
        {
            cat=a/b;
            r=a%b;
            aux=x;
            x=xa-cat*x;
            xa=aux;
            aux=y;
            y=ya-cat*y;
            ya=aux;
            a=b;
            b=r;
        }
        if (ok==1)
        {
            aux=xa;
            xa=ya;
            ya=aux;
        }
        g<<xa*(c/a);
    }
    else
        g<<"0\n";
    g.close();
    return 0;
}