#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<string>
#include<sstream>
#include<cmath>
#include<numeric>
using namespace std;


int main(){

  double h;
  double maxh = 0;
  double minh = 1000000;
  while( cin >> h ){
    maxh = max(maxh, h);
    minh = min(minh, h);
  }
  cout << maxh - minh << endl;

  return 0;
}