#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <functional>
#include <queue>
#include <set>
#include <map>
#include <numeric>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cctype>

#define rep(i, a) REP(i, 0, a)
#define REP(i, a, b) for(int i = a; i < b; ++i)

typedef long long ll;
typedef unsigned long long ull;
typedef std::pair<int, int> P;
typedef std::pair<P, int> PP;
struct edge{ int to, time, cost; };
const double esp = 1e-9;
const int infi = (int)1e+9 + 10;
const ll infll = (ll)1e+17 + 10;
const double infd = (double)1e+9;

double max = -infd, min = infd;

int main(){
	double d;
	while (std::cin >> d){
		if(d > max)max = d;
		if(d < min)min = d;
	}
	printf("%lf\n", max - min);
	return 0;
}