#include<fstream>
using namespace std;
ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");

void euclid(int a, int b, int& x, int& y)
{
	if (b == 0)
	{
		x = 1, y = 1;
	}
	else
	{
		int x1, y1;
		euclid(b, a%b, x1, y1);
		x = y1;
		y = x1 - a / b * y1;
	}
}

int main()
{
	int A, N;
	fin >> A >> N;
	int x, y;
	euclid(A, N, x, y);
	while (x < 0)
		x += N;
	fout << x;
	fin.close(), fout.close();
	return 0;
		
}