#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
const int N = 1e3 + 10;
int t, n, m, k, l, r, op, x, y, s, e;
int f[N];
void solve() {
    while (cin >> n) {
        t = 0;
        cin >> f[1];
        s = f[1];
        e = 0;
        for (int i = 2; i <= n; i++) {
            cin >> f[i];
            if (f[i-1] <= f[i]) {
                e = f[i];
            } else {
                t = max(t,e-s);
                s = f[i];
                e = 0;
            }
        }
        t = max(t,e-s);
        cout << t << "\n";
    }
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    solve();
    return 0;
}