#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>
#include <numeric>
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
constexpr long long MAX = 5100000;
constexpr long long INF = 1LL << 60;
constexpr int inf = 1000000007;
constexpr long long mod = 1000000007LL;
//constexpr long long mod = 998244353LL;
const long double PI = acos((long double)(-1));

using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;

bool div(string& s, int d) {
	int res = 0;
	for (int i = 0; i < s.size(); i++) {
		res = res * 10 + (s[i] - '0');
		res %= d;
	}
	return res == 0;
}
int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	*/

	string s; cin >> s;
	sort(s.begin(), s.end()); if (s[0] == s.back()) { cout << s << endl; return 0; }
	vector<int> v; for (int i = 0; i < s.size(); i++) v.push_back(s[i] - '0');
	sort(v.begin(), v.end()); v.erase(unique(v.begin(), v.end()), v.end());
	ll res = 0;
	ll g = 0;
	for (int i = 0; i < v.size(); i++) {
		for (int j = i + 1; j < v.size(); j++) {
			g = gcd(g, v[j] - v[i]);
		}
	}
	g *= 9;
	for (ll i = 1; i * i <= g; i++) {
		if (g % i == 0) {
			if (div(s, i)) chmax(res, i);
			if (div(s, g / i)) chmax(res, g / i);
		}
	}
	cout << res << endl;
	return 0;
}