#include <iostream>
#include <iomanip>
#include <ios>

using namespace std;

int main()
{
	double min, max;
  double x;

	cin >> x;
	min = x;
  max = x;

  while (cin >> x) {
    if (min > x) {
      min = x;
    } else if (max < x) {
      max = x;
    }
  }

	streamsize prec = cout.precision();
  cout << fixed << setprecision(1) << max - min 
       << setprecision(prec) << endl;

  return 0;
}