Problem:
Score : 100 points

Problem Statement

It is known that the area of a regular dodecagon inscribed in a circle of radius a is 3a^2.

Given an integer r, find the area of a regular dodecagon inscribed in a circle of radius r.

Constraints

1 \leq r \leq 100

r is an integer.

Input

Input is given from Standard Input in the following format:

r

Output

Print an integer representing the area of the regular dodecagon.

Sample Input 1

4

Sample Output 1

48

The area of the regular dodecagon is 3 \times 4^2 = 48.

Sample Input 2

15

Sample Output 2

675

Sample Input 3

80

Sample Output 3

19200

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

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
int min(int* b, int count, int n){
  int i;

  for(i=0; i<count; i++){
    if(n < b[i]){
      b[i] = n;
      return 1;
    }
  }

  return 0;
}

int main()
{
  int N;
  int* a;
  int b[10000];
  int i, count=1;
  scanf("%d", &N);

  a = (int*)malloc(sizeof(int)*N);

  for(i=0; i<N; i++){
    scanf("%d", &a[i]);
    if(i>=1){
      if(a[i-1] >= a[i]){
        b[count+1] = a[i-1];
        count = min(b, count, a[i]);
      }
    }
  }

  
  printf("%d", count);
   

  

  free(a);

  return 0;

}