#include<iostream>
#include<stdio.h>
#include<math.h>
using namespace std;
int main() {
	double n,max=0,min=1000000;
	while (cin >> n) {
		if (n > max)max = n;
		if (n <min)min = n;
	}
	cout << max - min << endl;
	return 0;
}
