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 JavaScript (judge verdict: Accepted)

var numbers = [];

var input = require('fs').readFileSync('/dev/stdin', 'utf8');
input.split('\n').forEach(function(line) {
  if (line !== '') {
    numbers.push(parseInt(line.trim(), 10));
  }
});

// Eliminate the first element which describes the size of the array.
numbers.shift();

var max = numbers[1] - numbers[0];
var min = numbers[0];
for (var i = 1; i < numbers.length; i += 1) {
  max = Math.max(max, numbers[i] - min);
  min = Math.min(min, numbers[i]);
};
console.log(max);