Problem:
Score : 100 points

Problem Statement

Given is an integer r.

How many times is the area of a circle of radius r larger than the area of a circle of radius 1?

It can be proved that the answer is always an integer under the constraints given.

Constraints

1 \leq r \leq 100

All values in input are integers.

Input

Input is given from Standard Input in the following format:

r

Output

Print the area of a circle of radius r, divided by the area of a circle of radius 1, as an integer.

Sample Input 1

2

Sample Output 1

4

The area of a circle of radius 2 is 4 times larger than the area of a circle of radius 1.

Note that output must be an integer - for example, 4.0 will not be accepted.

Sample Input 2

100

Sample Output 2

10000

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

#include <stdio.h>
#include <string.h>
 int main(void){
    int N,i;
    scanf("%d",&N);
    
    char s[N],a[N/2],b[N/2];
    
    if(N%2==0){
    for(i=0;i<N;i++){
      scanf("%s",&s[i]);
     }
      for(i=0;i<N;i++){
      if(i<N/2){
        a[i]=s[i];
      }
      else
        b[i-N/2]=s[i];
      }
      
     // printf("%s %s %s\n",s,a,b); aの値がおかしくなる
      if(strncmp(a,b,N/2)==0) 
        printf("Yes");
      else
        puts("No");
    }
     else    
    printf("No");
}