#include<iostream>
#include<algorithm>
using namespace std;
int main() {
	double d;
	cin >> d;
	double minn = d, maxx = 0;
	while (cin >> d) {
		minn = min(d, minn);
		maxx = max(d, maxx);
	}
	cout << maxx - minn << endl;
	char c;
	cin >> c;
}