#include <set>
#include <map>
#include <queue>
#include <stack>
#include <math.h>
#include <vector>
#include <stdio.h>
#include <fstream>
#include <iostream>
#include <string.h>
#include <limits.h>
#include <algorithm>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//#include <bits/stdc++.h>

#define ff first
#define ss second
#define ll long long
#define pb push_back
#define mp make_pair
#define inf 1000000007
#define mod 1000000007
#define pii pair <int, int>
#define all(x) x.begin(), x.end()
//#define tr(i,c) for(__typeof((c).begin()) i=(c).begin(); i!=(c).end(); i++)

//using namespace __gnu_pbds;

using namespace std;

//template <typename T> using ordered_set =  tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

ll mn = -1;

int ans;

int a, b;

int main()
{
	cin >> a >> b;
	for (int i = 1; i <= 1000000; i++)
	{
		ll gc  = __gcd(a+i, b+i);
		ll lc = (a+i)/gc;
		lc = lc*1LL*(b+i);
		
		if (mn == -1 || mn > lc)
			mn = lc, ans = i;
	}
	cout << ans;
}