/* ALDS1_1_D */
import java.io.*;

class Main
{
  public static void main(String[] args)
  {
    try{
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      int n = Integer.parseInt(br.readLine());
      int max = 0, min = 0;

      for(int i = 0; i < n; i++){
        int v = Integer.parseInt(br.readLine());
        if(i == 0){
          min = v;
          continue;
        }

        if(max < v - min || i == 1){
          max = v - min;
        }
        if(min > v) min = v;
      }
      System.out.println(max);
    }catch(Exception e){
      System.out.println(e);
    }
  }
}
/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