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

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

int main() {
	int i, b, t, a, d, x, y;
	f >> a >> b;
	euclid(a, b, &d, &x, &y);
	x = x % b;
	while (x < 0)
		x += b;
	g << x << '\n';

	return 0;
}