import java.util.Scanner;

public class Main{
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int minRate;
        int maxProfit = Integer.MIN_VALUE;
        int r = in.nextInt();
        minRate = r;

        for (int i = 1; i < n; i++) {
            r = in.nextInt();
            maxProfit = (maxProfit > r - minRate)? maxProfit : r - minRate;
            if(r < minRate) minRate = r;
        }
        System.out.println(maxProfit);
    }
}
/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