#include <iostream>
#include <stdio.h>
#include <math.h>

using namespace std;

double Max(double a,double b){
	if(a>=b){
		return a;
	}
	else{
		return b;
	}
}

double Min(double a,double b){
	if(a>=b){
		return b;
	}
	else{
		return a;
	}
}

int main(){

	double max=0,min=100000000;

	double tmp;

	while(cin>>tmp){
		if(tmp==0){
			break;
		}
		max = Max(max,tmp);
		min = Min(min,tmp);
	}

	cout<<(max-min)<<endl;
}

/*
Sample Input
3776.0
1819.0
645.2
2004.1
1208.6
Output for the Sample Input
3130.8
*/