#include<fstream>
using namespace std;
int a,b,x,y;
ifstream fin ("inversmodular.in");
ofstream fout("inversmodular.out");
int euclidex(int a,int b, int&x, int&y)
{
    if(b==0)
    {
        x=1;
        y=0;
        return a;
    }
    else
    {
        int d,x1,y1;
        d=euclidex(b,a%b,x1,y1);
        x=y1;
        y=x1-y1*(a/b);
        return d;
    }
}
int main ()
{
    int d;
    fin>>a>>b;
    d=euclidex(a,b,x,y);
    if(x<0)
    {
        x=b+x%b;
    }
    fout<<x;
    fin.close();
    fout.close();
    return 0;
}