#include<bits/stdc++.h>
using namespace std;

int main(){
	double h;
	vector<double>vh;
	vector<double>::iterator pvh=vh.begin();
	while(cin>>h){
		vh.push_back(h);		
		}
		sort(vh.begin(),vh.end());
		double a=*pvh;
		pvh=vh.end();
		double b=*pvh;
		double c=b-a;
		cout<<c<<endl;
		
		return 0;
	}