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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>

int main () {
    int i,s;
    s=0;
    int N,K;
    scanf("%d %d",&N,&K);
    int X[N];
    for (i=0;i<N;i++){
        scanf("%d",&X[i]);
    }
    for (i=0;i<N;i++){
        if(X[i] > K - X[i]){
            s += K - X[i];
        }else{
            s += X[i];
        }
    }
    printf("%d",2*s);
    return 0;
}