def solution(n):
answer = 0
n3 = ""
i = 0
while n != 0:
a = n % 3
n3 += str(a)
n /= 3
n = int(n)
i += 1
n3 = int(n3) # n3: n (3진법) & 앞뒤 반전(3진법)
i = 0
while n3 != 0:
a = n3 % 10
answer += a * (3 ** i)
n3 /= 10
n3 = int(n3)
i += 1
return answer