#include <algorithm>
#include <map>
#include <vector>
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cctype>
using namespace std;

#define REP(i,n) for(int i=0; i<n; ++i)
#define IREP(it,array) for(vector<int>::iterator it=array.begin(); it!=array.end(); ++it)

int main()
{
  cout.setf(ios::fixed, ios::floatfield);
  cout.precision(6);

  vector<double> nums;
  double h;
  while(cin>>h){
    nums.push_back(h);
  }

  vector<double>::iterator min_it = min_element( nums.begin(), nums.end() );
  vector<double>::iterator max_it = max_element( nums.begin(), nums.end() );

  cout << *max_it - *min_it << endl;

  return 0;
}