/* -*- coding: utf-8 -*-
 *
 * 1883.cc:  No.1883 SLASH - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int N = 3;

/* typedef */

/* global variables */

char s[N + 4];

/* subroutines */

/* main */

int main() {
  scanf("%s", s);
  sort(s, s + N);

  printf("%d\n", s[N - 1] - s[0]);
  return 0;
}