#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");
int a,b,x,y;
int euclid(int a,int b,int &x,int &y){
    if(b==0){
        x=1;
        y=0;
        return a;
    }
   int x0,y0;
    int r=euclid(b,a%b,x0,y0);
    x=y0;
    y=x0-y0*(a/b);
    return r;
}
int main()
{

    fin>>a>>b;
    euclid(a,b,x,y);
    x=x%b;
    if(x<0)
        x+=b;
    fout<<x;
}