#define _USE_MATH_DEFINES
#define _CRT_SECURE_NO_WARNINGS

#include <iostream>
#include <string>
#include <sstream>
#include <iomanip>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
#include <list>
#include <utility>
#include <numeric>

using namespace std;
typedef long long llong;
typedef unsigned long long ullong;

const ullong MOD = 1000000000 + 7;

int main()
{
	double maxh = 0, minh = 1000000;

	double h;
	for (; cin >> h;)
	{
		maxh = max(maxh, h);
		minh = min(minh, h);
	}

	cout << maxh - minh << endl;
}
