#include <iostream>


using namespace std;

int main()  {

	int n; cin >> n;
	int path[1001];
	int max = 0;
	int first = 0, last;

	for (int i = 0; i < n; i++)
		cin >> path[i];

	for (int i = 0; i < n; i++) {

		if (path[i+1] > path[i]) {
			if (first == 0) first = path[i];
			i++;
			while (path[i] > path[i-1]) {
				last = path[i]; i++;
			}
			i--;
		}

		if (last-first > max) max = last-first;
		first = 0; last = 0;
	}

	cout << max;
	return 0;

}