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 JavaScript (judge verdict: Wrong Answer)

const getMaxv = arr => {
  let j = 0;
  let maxv = -Infinity;
  let min = Infinity;
  for (j = 0; j < arr.length - 1; j++) {
    maxv = Math.max(maxv, arr[j] - min);
    min = Math.min(min, arr[j]);
  }
  console.log(maxv);
};

process.stdin.resume();
process.stdin.setEncoding("utf8");
let input_string = "";

process.stdin.on("data", chunk => {
  input_string += chunk;
});

process.stdin.on("end", () => {
  const lines = input_string.split("\n").filter(v => {
    return v !== "";
  });
  getMaxv(lines);
});