#include <bits/stdc++.h>
using ll = long long;
using llu = long long unsigned;

using namespace std;

int main() {
    string S;
    cin >> S;
    int ret = max({S[0], S[1], S[2]}) - min({S[0], S[1], S[2]});
    cout << ret << endl;
    return 0;
}