#include <stdio.h>
#include <math.h>
#include <iostream>

using namespace std;

int main() {

	double a;
	int i = 0;
	double MAX;
	double MIN;
	double kai;

	while(cin >> a) {
		if (i == 0) {
			MAX = a;
			MIN = a;
		} else {
			MAX = max(MAX,a);
			MIN = min(MIN,a);
		}
		i++;
	}

	kai = MAX - MIN;

	cout << kai << endl;

	return 0;
}