#include <bits/stdc++.h>
using namespace std;

string s;

set<int> S;
int main(){
	cin >> s;
	for (int i = 0; i < s.size(); i++){
		S.insert(s[i] - '0');
	}
	if (S.size() == 1){
		cout << s << endl;
		return 0;
	}
	int gc = 0;
	for (auto it = S.begin(); it != S.end(); it++){
		for (auto itt = S.begin(); itt != S.end(); itt++){
			int sa = abs((*it) - (*itt));
			gc = __gcd(gc, sa);
		}
	}
	cout << gc << endl;
	return 0;
}