import java.util.*;

class Main{
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.nextLine());
        int[] r = new int[n];
        for(int x=0; x < n; x++){
            r[x] = Integer.parseInt(sc.nextLine());
        }
        int maxv = -2000000000;
        int minv = r[0];

        for(int i = 1; i < n; i++){
            maxv = Math.max(maxv, r[i] - minv);
            minv = Math.min(minv, r[i]);
        }
        System.out.println(maxv);

    }
}
/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