#include <iostream>
#include <cassert>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  string s; cin >> s;
  int ma = -1, mi = 10;
  for (int i = 0; i < 3; i++) {
    ma = max(ma, s[i] - '0');
    mi = min(mi, s[i] - '0');
  }
  cout << ma - mi << endl;
  return 0;
}