#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {

  vector<double> yama;
  double input;

  while( cin >> input ) {

    yama.push_back(input);

  }

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

  cout << yama[ yama.size()-1 ] - yama[ 0 ] << endl;

  return 0;

}