#include<iostream>
using namespace std;
int main(){
	int i = 0, h[50] ={};
	double height;
	
	while(cin >> height){
		h[i] == height;
		i ++;
	}
	
	int N = sizeof(h);
	
	double max = h[0], min = h[0];
	for(int i = 0; i < N; i++){
		if(max < h[i]) max = h[i];
	}
	for(int i = 0; i < N; i++){
		if(min > h[i]) min = h[i];
	}
	
	double ans = max - min;
	cout << ans << endl; 
}