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>

int main(){
  int n,i,t1=0,t2=0;
  scanf("%d",&n );
  int num[n];
  for(i=0;i<n;i++){
     scanf("%d",&num[i]);
     if(t1<num[i]) t1=num[i];
     else if(t2<num[i]) t2=num[i];
   }
   for(i=0;i<n;i++){
     if(num[i]==t1) printf("%d",t2 );
     else printf("%d",t1 );
   }
   return 0;
}