#include <iostream>
using namespace std;

int main()
{
  double a, max, min;
  max = 0;
  min = 10000000;
  while (cin >> a){
    if (max < a){
      max = a;
    }
    if (min > a){
      min = a;
    }
  }
  cout << max - min << endl;
  return 0;
}