#include <iostream>
#include <set>
using namespace std;
int main(){
	double h;
	set<double> high;
	while(cin>>h){
		high.insert(h);
	}
	set<double>::iterator a=high.begin();
	set<double>::iterator b=high.end();
	double c=*b-*a;
	cout<<c<<endl;
	return 0;
}