Problem:
Score : 100 points

Problem Statement

We have an N \times N square grid.

We will paint each square in the grid either black or white.

If we paint exactly A squares white, how many squares will be painted black?

Constraints

1 \leq N \leq 100

0 \leq A \leq N^2

Inputs

Input is given from Standard Input in the following format:

N
A

Outputs

Print the number of squares that will be painted black.

Sample Input 1

3
4

Sample Output 1

5

There are nine squares in a 3 \times 3 square grid.
Four of them will be painted white, so the remaining five squares will be painted black.

Sample Input 2

19
100

Sample Output 2

261

Sample Input 3

10
0

Sample Output 3

100

As zero squares will be painted white, all the squares will be painted black.

Solution in Scala (2.11.7) (judge verdict: Accepted)

import java.io.{PrintWriter, _}
import java.util
import java.util._


object Main {
  def main(args: Array[String]): Unit = {
    val inputStream = System.in
    val outputStream = System.out
    val in = new InputReader(inputStream)
    val out = new PrintWriter(outputStream)
    val solver = new Task
    solver.solve(1, in, out)
    out.close()
  }

  class Task {
    def solve(testNumber: Int, in: InputReader, out: PrintWriter): Unit = {
      val a = in.nextInt
      val b = in.nextInt
      out.println(a * a - b)
    }
  }

  class InputReader(val stream: InputStream) extends AutoCloseable {
    //reader = new BufferedReader(new FileReader(stream), 32768);
    private val reader = new BufferedReader(new InputStreamReader(stream), 32768)
    private var tokenizer = new StringTokenizer("")


    def next: String = {
      while ( {
        tokenizer == null || !tokenizer.hasMoreTokens
      }) try
        tokenizer = new StringTokenizer(reader.readLine)
      catch {
        case e: IOException =>
          throw new RuntimeException(e)
      }
      tokenizer.nextToken
    }

    def nextLine: String = {
      try
        return reader.readLine
      catch {
        case e: IOException =>
          e.printStackTrace()
      }
      ""
    }

    def nextInt: Int = next.toInt

    def nextLong: Long = next.toLong

    override def close(): Unit = {
    }
  }

}