#include <iostream>

using namespace std;

int main(void){
	double a, mx, mn;
	cin >> a;
	mx = mn = a;
	while(1){
		if(cin.eof() == -1){
			break;
		}
		cin >> a;
		mx = max(mx,a);
		mn = min(mn,a);
	}
	cout << mx - mn << endl;
	return 0;
}