# 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){
    int r,xa,ya;
    if(!b){
        x=1;
        y=0;
        return a;
    }
    r=euclid(b,a%b,xa,ya);
    x=ya;
    y=xa-(a/b)*ya;
    return r;
}
int main () {
    fin>>a>>b;
    euclid(a,b,x,y);
    x%=b;
    if(x<0)
        x+=b;
    fout<<x<<"\n";
    return 0;
}