#include <iostream>
#include <climits>
using namespace std;
int main(){
	double n;
	double maxN = -(1<<30), minN = 1<<30;
	while(cin >> n){
		maxN = max(maxN, n);
		minN = min(minN, n);
	}
	cout << maxN - minN << endl;
	return 0;
}