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

using namespace std;

int main(){
  vector<double> heightarray;
  double height;
  while(cin>>height){
    heightarray.push_back(height);
  }
  sort(heightarray.begin(),heightarray.end());
  cout<<-heightarray[0]+heightarray[heightarray.size()-1]<<endl;
}