#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <sstream>
#include <vector>
#include <string>
#include <iomanip>
#include <bitset>
#define INF	100000000
#define pb	push_back
#define fi first
#define sec second
#define SS stringstream
using namespace std;
typedef pair<int, int> P;
typedef long long int	ll;

vector<double> vec;

int main(){
	double temp;
	while(cin >> temp) vec.pb(temp);
	sort(vec.begin(), vec.end());
	cout << vec[vec.size()-1]-vec[0] << endl;
}