#include <bits/stdc++.h>
using namespace std;
static const int MAX = 20000;
int main() {
  int R[MAX], n;
  cin >> n;
  for (int i = 0; i < n; i++) cin >> R[i];
  int maxv = -2000000000;
  int minv = R[0];
  for (int i = 1; i < n; i++) {
    maxv = max(maxv, R[i] - minv);
    minv = min(minv, R[i]);
  }
  cout << maxv << endl;
  return 0;
}
