#include<fstream>

using namespace std;

ifstream f("inversmodular.in");
ofstream g("inversmodular.out");

int cmmdc(int a,int b,int &x,int &y)
{
    if(b==0)
    {
        x=1;
        y=0;
        return a;
    }

    int x0,y0,d;
    d=cmmdc(b,a%b,x0,y0);
    x=y0;
    y=x0-(a/b)*y0;
    return d;
}

int x,y,a,b;

int main()
{
    f>>a>>b;
    cmmdc(a,b,x,y);
    while(x<0)
        x+=b;

    g<<x<<"\n";

    f.close();
    g.close();

    return 0;
}