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

int main(){
  int num;
  cin >> num;
  int a, b, c;
  a = num / 100;
  c = num % 10;
  b = num /10 % 10;
  cout << max(max(a, b), c) - min(min(a, b), c) << endl;
  return 0;
}