#include <fstream>
using namespace std;
ifstream f("inversmodular.in");
ofstream g("inversmodular.out");
long long a,b,x,y,z=1,r,c,in;
int main()
{
    f>>a>>b;in=b;
    while(a)
    {
      r=b%a;
      c=b/a;
      b=a;
      a=r;
      x=y-c*z;
      y=z;
      z=x;
    }
    while(y<0)
        y+=in;
    g<<y;
    return 0;
}