import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws Exception {
		//??\??????????????????
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        //????????????????????°?????????
        int num =Integer.parseInt(br.readLine());
        //??????????°???? ???????????????????¨??????????
        int min = Integer.parseInt(br.readLine());
        //?????§?????? ????????????????????????????????????????????§??????????????????????????????????¨??????????
        int maxProfit = -1000000000;
        int currentNum = 0;
        for(int i = 1 ; i < num ; i++){
        	currentNum = Integer.parseInt(br.readLine());
        	maxProfit = Math.max(maxProfit, currentNum - min);
        	min = Math.min(min, currentNum);
        }
        
        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