#include <iostream>

using namespace std;

int gcd(int x, int y) {
	while (y != 0) {
		int t = y;
		y = x % y;
		x = t;
	}
	return x;
}
int main() {
	int a, b;
	cin >> a >> b;
	int minlcm=INT32_MAX, minN;
	int N = 1;
	while (N < minlcm) {
		int lcm = (int)((a + N)*(b + N)) / gcd(a + N, b + N);
		if (lcm < minlcm) {
			minN = N;
			minlcm = lcm;
		}
		N++;
	}
	cout << minN;

}