from collections import defaultdict
from itertools import repeat
import sys
import os

sys.setrecursionlimit(100000)
is_local = "TERM_PROGRAM" in os.environ
input = sys.stdin.readline
INF = float('inf')
MOD = 998244353

def debug(*args, **kwargs):
    if is_local:
        print(*args, **kwargs)
def I(): return input().rstrip()
def IS(): return input().split()
def II(): return int(input())
def IIS(): return map(int, input().split())
def LIIS(): return list(map(int, input().split()))

jun_map = {0: 1, 1: 2, 2: 0}
rev_map = {0: 2, 2: 1, 1: 0}

def main():
    n = II()
    va = LIIS()
    rev = n % 2 == 0
    one_array = [0]
    two_array = [0]
    cnt = 0
    for _ in range(2*n):
        one_array.append(step(one_array[-1], rev))
        two_array.append(step(two_array[-1], not rev))
        cnt += 1
        if cnt == 2:
            rev = not rev
            cnt = 0

    one_array2 = []
    one_array3 = []
    two_array2 = []
    two_array3 = []
    for i in range(2*n+1):
        one_array2.append(jun_map[one_array[i]])
        one_array3.append(rev_map[one_array[i]])
        two_array2.append(jun_map[two_array[i]])
        two_array3.append(rev_map[two_array[i]])
    if va == one_array or va == one_array2 or va == one_array3:
        print(1)
    elif va == two_array or va == two_array2 or va == two_array3:
        print(2)
    else:
        print(0)


def step(x, rev):
    if rev:
        return rev_map[x]
    else:
        return jun_map[x]


if __name__ == "__main__":
    main()