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 (Clang 3.8.0) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <stdlib.h>

int remax(int *a,int q,int N){
	int max = 0;

	for(int t=0;t<N;t++){

		if(t != q) {
			if(a[t] > max) max = a[t];
		}
	}

	return max;

}

int main(void){

	int N=0,i;

	scanf("%d" ,&N);
	int *a;

	a = calloc(N,sizeof(int));

	for(i=0;i<N;i++){
		scanf("%d",&a[i]);
	}


	for(i=0;i<N;i++){

		printf("%d\n",remax(a,i,N));
	}

	return 0;
}