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: Accepted)

#include <stdio.h>
#include <math.h>

int main(void){

  int r[200000], i, j, n, co = 1000000001, coo = -1000000000;

  scanf("%d", &n);
  for(i = 0; i < n; i++){
    scanf("%d", &r[i]);
  }

  for(i = 0; i < n; i++){
    if(co < r[i]) continue;
    co = r[i];
    for(j = 1+i; j < n; j++){
      if(coo < r[j] - r[i]){
	coo = r[j] - r[i];
      }
    }
  }

  printf("%d\n", coo);

  return 0;
}