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

using namespace std;

int main(void){
  double d;
  vector<double> v;

  while(cin >> d){
    v.push_back(d);
  }

  sort(v.begin(), v.end());

  cout << v.at(v.size() - 1) - v.at(0) << endl;
  

  return 0;
}