#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int max_dist(vector<int> &a, const int d)
{
    const int n = a.size();

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

    int l = 0;
    int max_d = 0;
    for (int r = 1; r < n; r++) {
        while (a[r] - a[l] > d) {
            l++;
        }

        int curr_d = a[r] - a[l];
        if (max_d < curr_d) {
            max_d = curr_d;
        }
    }

    return max_d;
}

int main(void)
{
    int n;
    cin >> n;

    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }

    int d;
    cin >> d;

    cout << max_dist(a, d) << endl;

    return 0;
}