#include <stdio.h>


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

int main()
{
	freopen("inversmodular.in", "r", stdin);
	freopen("inversmodular.out", "w", stdout);
	int a, b;
	scanf("%d %d", &a, &b);
	int d, x, y;
	euclid(a, b, &d, &x, &y);
	while (x < 0)
		x += b;
	printf("%d\n", x);
	return 0;
}