#include <fstream>

using namespace std;
ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");
int a,b,x,y;
int cmmdc(int a,int b, int &x, int &y)
{
    int x0,y0,d;
    if(!b)
    {
        x=1;
        y=0;
        return a;
    }
    d=cmmdc(b, a % b, x0, y0);
    x = y0;y = x0-(a / b) * y0;
    return d;
}
int main()
{
    fin>>a>>b;
    cmmdc(a,b,x,y);
    while(x<0)
        x+=b;
    fout<<x;
    return 0;
}