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 JAVA (judge verdict: Accepted)


import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
      int n = in.nextInt();

      int max = 0;
      int min = 0;

      for (int i = 0; i < n; i++) {
        int newScan = in.nextInt();

        if (min == 0 ) {
          min = newScan;
        } else if( min > newScan) {

          int tmp =  newScan - min;
          if (max == 0 || tmp > max) {
            max = tmp;
          }
          min = newScan;

        } else {
          int tmp = newScan - min;
          if (max == 0 || tmp > max) {
            max = tmp;
          }

        }
      }


      System.out.println(max);
    }
}