#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using pii = pair<int, int>;

int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  
  double h, h_max = 0, h_min = 1e7;
  while (cin >> h) {
    h_max = max(h_max, h);
    h_min = min(h_min, h);
  }
  cout << h_max - h_min << endl;

  return 0;
}
