#include <iostream>

using namespace std;

int main(int argc, char *argv[]) {
  double min, max, tmp;

  cin >> tmp;
  min = max = tmp;
  while (cin >> tmp) {
    if (tmp < min)
      min = tmp;
    if (tmp > max)
      max = tmp;
  }
  cout << max-min << endl;
  return 0;
}