#include "bits/stdc++.h"
using namespace std;

const int N = 1010;
vector<int> a(N), b;
int n;

int main() {
    while (cin >> n) {
        int res = 0;
        a.resize(n);
        for (int i = 0; i < n; i ++) cin >> a[i];

        for (int i = 0; i + 1 < n;) {
            int j = i + 1;
            if (a[j] < a[i]) {
                i ++;
                continue;
            }
            while (j < n && a[j] >= a[j - 1]) j ++;

            if (j - i >= 2) res = max(res, a[j - 1] - a[i]);
            i = j;
        }
        cout << res << '\n';
    }
    return 0;
}