Problem:
Score : 300 points

Problem Statement

You are given two integer sequences of length N: a_1,a_2,..,a_N and b_1,b_2,..,b_N.
Determine if we can repeat the following operation zero or more times so that the sequences a and b become equal.

Operation: Choose two integers i and j (possibly the same) between 1 and N (inclusive), then perform the following two actions simultaneously:

Add 2 to a_i.

Add 1 to b_j.

Constraints

1 ≤ N ≤ 10 000

0 ≤ a_i,b_i ≤ 10^9 (1 ≤ i ≤ N)

All input values are integers.

Input

Input is given from Standard Input in the following format:

N
a_1 a_2 .. a_N
b_1 b_2 .. b_N

Output

If we can repeat the operation zero or more times so that the sequences a and b become equal, print Yes; otherwise, print No.

Sample Input 1

3
1 2 3
5 2 2

Sample Output 1

Yes

For example, we can perform three operations as follows to do our job:

First operation: i=1 and j=2. Now we have a = \{3,2,3\}, b = \{5,3,2\}.

Second operation: i=1 and j=2. Now we have a = \{5,2,3\}, b = \{5,4,2\}.

Third operation: i=2 and j=3. Now we have a = \{5,4,3\}, b = \{5,4,3\}.

Sample Input 2

5
3 1 4 1 5
2 7 1 8 2

Sample Output 2

No

Sample Input 3

5
2 7 1 8 2
3 1 4 1 5

Sample Output 3

No

Solution in Scala (2.11.7) (judge verdict: Wrong Answer)

import java.util.Scanner

/**
  * Created by 80011714 on 2018/2/5.
  */
object Main {

  def solve(sc: Scanner): Unit = {
    val x, y = sc.nextLong()
    println(if (x % y == 0) (-1) else {
      var i = 1
      while (i * x % y == 0) (i += 1)
      i * x
    })
  }

  def task2(n: Int, left: Array[Long], right: Array[Long]): String = {
    if (n == 1)
      return if (left.head <= right.head) "Yes" else "No"

    if (left.head < right.head) {
      val right_add_count = (right.head - left.head) / 2
      right(1) += right_add_count
    } else if (left.head > right.head) {
      val left_add_count = left.head - right.head
      left(1) += (left_add_count * 2)
    }
    return task2(n - 1, left.tail, right.tail)
  }

  def main(args: Array[String]): Unit = {
//    val sc: Scanner = new Scanner(System.in)

    val N = scala.io.StdIn.readInt
    val a = scala.io.StdIn.readLine.split(" ").map(_.toLong).toSeq.toArray
    val b = scala.io.StdIn.readLine.split(" ").map(_.toLong).toSeq.toArray

    println(task2(N, a, b))
  }
}