from itertools import combinations as combs
from math import factorial as fact
def Comb(A,B):
	return fact(A)/(fact(A-B)*fact(B))

N = int(raw_input())
MAX_N = 99
ans = 0.0
card_num = xrange(25)
for i in range(max(5,25 + N - MAX_N),min(N+1,26)):
	prob = Comb(74,N-i)
	for call in combs(card_num,i):
		call = set(call)
		line = 0
		for i in range(5):
			for j in range(5):
				if i*5 + j in call:
					continue
				break
			else:
				line += 1
		for i in range(5):
			for j in range(5):
				if i + 5*j in call:
					continue
				break
			else:
				line += 1
		for i in range(5):
			if i + 5*i in call:
				continue
			break
		else:
			line += 1
		for i in range(5):
			if i + 5*(4-i) in call:
				continue
			break
		else:
			line += 1
		ans += prob * line
print ans / Comb(MAX_N, N)