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

using namespace std;

int main()
{
  vector<double> seq;

  double tmp;
  while (cin >> tmp)
    seq.push_back(tmp);

  double vmax = *max_element(seq.begin(), seq.end());
  double vmin = *min_element(seq.begin(), seq.end());

  cout << vmax - vmin << endl;
}
