#include <iostream>
#include <queue>
#include <stack>
#include <vector>
#include <stdio.h>
#include <algorithm>
#include <string.h>
#include <string>
#include <cmath>
#include <complex>
#include <map>
using namespace std;

#define rep(i,n) for(int i=0;i<int(n);++i)
#define ALL(v) (v).begin(),(v).end()
#define PB push_back
#define EPS 1e-8

static const double PI=6*asin(0.5);
typedef complex<double> P;
typedef long long ll;


double MIN,MAX;

int main(){
	double t;
	cin>>t;
	MAX=MIN=t;
	while(cin>>t){
		MAX=max(MAX,t);
		MIN=min(MIN,t);
	}
	cout<<MAX-MIN<<endl;
	return 0;
}