#include <bits/stdc++.h> using namespace std; const int N = 1e6 + 005; int a[N], d[N]; int main() { int n, maxn = 0; cin >> n; for (int i = 1; i <= n; i++) cin >> a[i]; for (int i = 1; i <= n; i++) { int minn = -1e9; for (int j = i; j <= n; j++) minn = max(minn, a[i]); if (minn = a[i]) maxn = max(maxn, a[i]); else maxn = max(maxn, minn - a[i]); } cout << maxn << endl; return 0; }