#include <iostream>
#include <string>
#include <algorithm>
#include <vector>

using namespace std;
int main(){

  vector<double> n;  
  double a;
  int i=0;
  while(cin >> a){
    n.push_back(a);
    i++;
  }
  sort(n.begin(),n.end());

  cout << n[i-1] - n[0] << endl;

 
 return 0;
}