#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <string>
#include <iostream>
#include <map>
#include <iomanip>
#include <stack>
#include <sstream>
#include <queue>
#include <set>
#include <functional>

#define endl '\n'
#define eps 1e-9
#define ll long long int

using namespace std;

ll gcd(ll x, ll y){
	if (y == 0) return x;
	if (x >= y) return gcd(y, x%y);
	return gcd(y, x);
}

ll lcm(ll x, ll y){
	return x*y/gcd(x, y);
}

int main(){
	ll A, B;
	cin >> A >> B;
	ll temp = 1e18;
	ll ret = 1;
	for (ll N = 1; N < max(A, B); N++){
		ll t = lcm(A+N, B+N);
		if (t < temp) {ret = N; temp = t;}
	}
	cout << ret;
}