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 Python (3.4.3) (judge verdict: Runtime Error)

import math
import sys
 
 
def Knight():
    def check(d):
        if not ((d[0] % 3 == 0 and d[1] % 3 == 0) or (d[0] % 3 == 1 and d[1] % 3 == 2) or (d[0] % 3 == 2 and d[1] % 3 == 1)):
            print(0)
            sys.exit()
    d = list(map(int, input().split()))
    check(d)
 
    x = d[0]
    y = d[1]
    diff = x - y if x > y else y - x  # aとbの回数の差
    d2 = [x - diff, y - diff * 2] if x < y else [x - diff * 2, y - diff]
    r = d2[0] // 3
 
    def cmb(n, r, mod):
        r = min(r, n-r)
        return g1[n] * g2[r] * g2[n-r] % mod
 
    mod = 10**9+7  # 出力の制限
    N = x if x > y else y
    g1 = [1, 1]  # 元テーブル
    g2 = [1, 1]  # 逆元テーブル
    inverse = [0, 1]  # 逆元テーブル計算用テーブル
 
    for i in range(2, N + 1):
        g1.append((g1[-1] * i) % mod)
        inverse.append((-inverse[mod % i] * (mod//i)) % mod)
        g2.append((g2[-1] * inverse[-1]) % mod)
 
    a = cmb(r*2+diff, r, mod)
 
    print(a)
 
 
Knight()