import java.util.*;

public class Main{
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        long min = sc.nextInt();
        long ret = -1000000001;

        for (int i = 1; i<n; i++){
            long r = sc.nextInt();
            if (r - min > ret) ret = r - min;
            if (r < min) min = r;
        }
        System.out.println(ret);
    }
}
/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