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