#include <iostream>
#include <string>
#include <algorithm>
#include <functional>
#include <vector>
#include <utility>
#include <cstring>
#include <iomanip>
#include <numeric>
#include <cmath>
#include <queue>
#include <map>
using namespace std;
typedef long long ll;
const int INF = 1<<30; 
const int MOD = 1e9 + 7;
const int dy[] = {1, 0, -1, 0};
const int dx[] = {0, 1, 0, -1};
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    double x;
    double max_n = -INF;
    double min_n = INF;
    while(cin >> x)
    {
        max_n = max(x, max_n);
        min_n = min(x, min_n);
    }
    cout << max_n - min_n << endl;
    return 0;
}


