import sys
input = sys.stdin.readline
def iinput(): return int(input())
def sinput(): return input().rstrip()
def i0input(): return int(input()) - 1
def linput(): return list(input().split())
def liinput(): return list(map(int, input().split()))
def miinput(): return map(int, input().split())
def li0input(): return list(map(lambda x: int(x) - 1, input().split()))
def mi0input(): return map(lambda x: int(x) - 1, input().split())
INF = 10**20
MOD = 1000000007

def levi(x):
    if x == (0, 1, 2) or x == (1, 2, 0) or x == (2, 0, 1):
        return 1
    elif x == (2, 1, 0) or x == (1, 0, 2) or x == (0, 2, 1):
        return 2
    else:
        return 0
N = iinput()
P = liinput()
Q = []
for i in range(2 * N - 1):
    Q.append(levi((P[i], P[i + 1], P[i + 2])))

if len(Q) == 1:
    print(Q[0])
    exit(0)

for q in Q[1::2]:
    if q != 0:
        exit(print(0))

for q, r in zip(Q[::2], Q[2::2]):
    if q == r or q == 0 or r == 0:
        exit(print(0))

if N % 2:
    print(Q[0])
else:
    if Q[0] == 1:
        print(2)
    else:
        print(1)