Problem:
MathJax.Hub.Config({ tex2jax: { inlineMath: [["$","$"], ["\\(","\\)"]], processEscapes: true }});

Maximum Profit

You can obtain profits from foreign exchange margin transactions. For example, if you buy 1000 dollar at a rate of 100 yen per dollar, and sell them at a rate of 108 yen per dollar, you can obtain (108 - 100) × 1000 = 8000 yen.

Write a program which reads values of a currency $R_t$ at a certain time $t$ ($t = 0, 1, 2, ... n-1$), and reports the maximum value of $R_j - R_i$ where $j > i$ .

Input

The first line contains an integer $n$. In the following $n$ lines, $R_t$ ($t = 0, 1, 2, ... n-1$) are given in order.

Output

Print the maximum value in a line.

Constraints

$2 \leq n \leq 200,000$

$1 \leq R_t \leq 10^9$

Sample Input 1

6
5
3
1
3
4
3

Sample Output 1

3

Sample Input 2

3
4
3
2

Sample Output 2

-1

Solution in JAVA (judge verdict: Time Limit Exceeded)

import java.util.Scanner;

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

        for (int i = 0; i < length; i++) {
            numbers[i] = sc.nextInt();
        }

        int max = numbers[1] - numbers[0];
        for (int i = length - 1; i >= 1; i--) {
            for (int j = i - 1; j >= 0; j--) {
                int diff = numbers[i] - numbers[j];
                if (diff >= max) {
                    max = diff;
                }
            }
        }

        System.out.println(max);
    }
}