#include <iostream>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <bitset>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cmath>

using namespace std;

int main(){

	double n;
	double max = 0, min = 20000000;
	while(cin >> n){
		if(cin.eof()) break;
		if(max < n) max = n;
		if(min > n) min = n;
	}

	printf("%0.1f\n", max - min);

	return 0;
}