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

 ifstream fin("inversmodular.in");
 ofstream fout("inversmodular.out");
 int a,b,x,y,d;
void euclid(int a, int b, int &x, int &y,int &d)
{
    if(b==0)
    {
        d=a;
        x=1;
        y=0;
    }
    else
    {
        int x0,y0;
        euclid(b, a%b, x0,y0,d);
        x=y0;
        y=x0-(a/b)*y0;
    }
}

 int main()
 {
     fin>>a>>b;
     euclid(a,b,x,y,d);
     while(x<0)
     {
         x+=b;
     }
     fout<<x;
     return 0;
 }