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

public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine()); // 整数の個数
		int minNum = Integer.parseInt(br.readLine()); // 最小値
		int maxNum = -1000000000; // 差額の最大値
		for (int i = 1; i < n; i++) {
			int r = Integer.parseInt(br.readLine());
			maxNum = Math.max(maxNum, r - minNum);
			minNum = Math.min(minNum, r);
		}
		System.out.println(maxNum);

	}

}

/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