import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int minR = 0;
        int maxDiff = -1000000000;
        for (int i = 0; i < n; i++) {
            int r = scanner.nextInt();
            if (i == 0) {
                minR = r;
                continue;
            }
            int diff = r - minR;
            if (maxDiff < diff) {
                maxDiff = diff;
            }
            if (r < minR) {
                minR = r;
            }
        }
        System.out.println(maxDiff);
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz