Problem:
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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: Time Limit Exceeded)

#include<stdio.h>


int main()
{
	int n;
	int amax;
	int C[200000];
	int cmin;

	scanf("%d", &n);
	for (int t = 0; t < n; t++)
	{
		scanf("%d", &C[t]);
	}

	amax = C[1] - C[0];
	cmin = C[0];
	
	for (int j = 1; j < n-1 ; j++)
	{

		if (C[j] < cmin)
		{
			cmin = C[j];
		}
		
		for (int i = j + 1; i < n; i++)
		{
			int comp = C[i] - cmin;
			if (amax < comp)
			{
				amax = comp;
			}
		}
		
	}
		printf("%d\n", amax);	
			

	return 0;
}