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 C# (judge verdict: Wrong Answer)

using System;


public class hello
{
    public static void Main()
    {

        
        var n = int.Parse(Console.ReadLine().Trim());
        var ary = new int[n];
        var dmax = 0;

        for (int i = 0; i < n; i++)
            ary[i] = int.Parse(Console.ReadLine().Trim());
        for (int i = 1   ; i < n; i++)
        {
            for (int j = i-1; j >=0; j--)
            {
                if (ary[j] >= ary[i]) break;
                if (ary[i] - ary[j] > dmax) dmax = ary[i] - ary[j];
            }
        }
        Console.WriteLine(dmax);
    }
}