#include <bits/stdc++.h>

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