#include <iostream>
#include <fstream>

using namespace std;
ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");
void cmmdc(int a,int b,int &k,int &l)
{   int kp,lp;
    if(b==0)
       {
           l=0;
           k=1;
           return;
       }
    cmmdc(b,a%b,kp,lp);
    k=lp;
    l=kp-lp*(a/b);

}
int main()
{   int a,x,y,n;
       fin>>a>>n;
       cmmdc(a,n,x,y);
       while(y<0)
        y+=a;
       fout<<y;

    return 0;
}