#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main(){

  vector<double>in;
  double a;
  int count=0;
  while(cin >> a!='\0'){
    in.push_back(a);
    count++;
  }
  //cout << in[0] << endl;

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

  //cout << count << endl;

  cout << in[count-1]-in[0]<< endl;

}