def f(a,b,c):
    if (a,b,c) in ((0,1,2),(1,2,0),(2,0,1)):return 1
    elif (a,b,c) in ((2,1,0),(1,0,2),(0,2,1)):return 2
    else:return 0

N = int(input())
A = list(map(int,input().split()))

N_2 = N-1
A_2 = []

for i in range(2*N-1):
    A_2.append(f(A[i],A[i+1],A[i+2]))

if N_2%2==0:
    one = [1,0,2,0]*(N_2//2)+[1]
    two = [2,0,1,0]*(N_2//2)+[2]
else:
    one = [2,0,1,0]*(N_2//2)+[2,0,1]
    two = [1,0,2,0]*(N_2//2)+[1,0,2]

print(1 if A_2==one else 2 if A_2==two else 0)