#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
  int N;
  cin>>N;
  int a = N%10;
  int b = N/100;
  int c = (N-a-b*100)/10;
  cout<<max(max(a,b),c)-min(min(a,b),c)<<endl;
}