#include<string>
#include<vector>
#include<iostream>
#include<sstream>
#include<cstdio>
#include<cstdlib>
#include<functional>
#include<algorithm>
#include<stack>
#include<queue>
#include<deque>
#include<set>
#include<map>
#include<utility>
#include<cmath>
#include<ctime>
#include<complex>

using namespace std;

#define REP(i,s,e) for(int i=int(s);i<=int(e);i++)
#define rep(i,n) for(int i=0;i<int(n);i++)

int main(){

	double h;
	vector<double>v;

	while(cin >> h){

    v.push_back(h);

	}

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

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

	return 0;
}