#include <fstream>

using namespace std;

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

void euclidextins(int a,int b,int &x,int &y,int &d){
	if(!b){
		d=a;
		x=1;
		y=0;
		return;
	}
	int x0,y0;
	euclidextins(b,a%b,x0,y0,d);
	x=y0;
	y=x0-(a/b)*y0;
}

int main(){
	int a,b,x,y,d,rez;
	in>>a>>b;
	euclidextins(a,b,x,y,d);
	rez=x%b;
	while(rez<0)
		rez+=b;
	out<<rez;
	return 0;
}