#include<iostream>
#include<cmath>
#include<algorithm>
#include<string>
#include<map>
using namespace std;
int main() {
    int n;
    while (cin >> n) {
        int arr[1000], sum = 0, Max = 0;
        for (int i = 0;i < n;i++) {
            cin >> arr[i];
        }
        for (int i = 0;i < n;i++) {
            sum = 0;
            for (int j = i;j < n - 1;j++) {
                if (arr[j] <= arr[j + 1]) {
                    sum += arr[j + 1] - arr[j];
                }
                else {
                    break;
                }
            }
            Max = max(Max, sum);
        }
        cout << Max << endl;
    }
    return 0;
}