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());
        int max = Integer.MIN_VALUE;
        int prospectMin = 0;
        for (int i = 0; i < n; i++) {
            int a = Integer.parseInt(br.readLine());
            if (i == 0) {
                prospectMin = a;
                continue;
            }
            int profit = a - prospectMin;
            if (profit > max) {
                max = profit;
            }
            if (a < prospectMin) {
                prospectMin = a;
            }
        }
        System.out.println(max);

    }
}
/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