#include<iostream>
#include<algorithm>
#include<stdio.h>
using namespace std;

int main(){
	float big = 0, small = 100000;
	float input[1000];
	int i=0;

	while(scanf("%f", &input[i]) != EOF){
		big = max(big, input[i]);
		small = min(small, input[i]);
		i++;
	}
	cout << big - small << endl;
}