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 Haskell (GHC 7.10.3) (judge verdict: Accepted)

import Control.Monad
import Control.Applicative
import Data.List

-- String, Int, Char, IO

-- e.g.
-- 1
-- [a] <- map read . words <$> getline => [1] -> a == 1
-- 1
-- a <- readlLn
-- 1 2 3
-- lst <- map read . words <$> getLine => [1, 2, 3]
-- 1 2 3
-- [l, m, n] <- map read . words <$. getLine :: IO [Int] => [1, 2, 3]
-- 'a'
-- c <- getChar => c == 'a'

main :: IO()
main = do
  n <- readLn :: IO Int
  a <- readLn :: IO Int
  print $ solve n a

solve :: Int -> Int -> Int
solve n a = n*n - a