#include <iostream>
#include <vector>
#include <list>
#include <algorithm>
#include <string>
#include <stack>
#include <iomanip>
#include <numeric>
#include <queue>
#include <climits>
#include <complex>
#include <cmath>
#include <map>
using namespace std;
using ll = long long;
#define MOD 1000000007
#define INF 1LL << 59

int main()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    cout << fixed << setprecision(3);

    vector<double> v;
    double n;
    while (cin >> n)
        v.push_back(n);

    sort(v.begin(), v.end());

    cout << v[v.size() - 1] - v[0] << endl;
    return 0;
}
