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

s1 = {(0,1,2),(1,2,0),(2,0,1)}
s2 = {(2,1,0),(1,0,2),(0,2,1)}

import sys
def calc(l):
    n = len(l)
    ans = []
    for i in range(1,n - 1):
        if (l[i-1],l[i],l[i+1]) in s1:
            ans.append(1)
        elif (l[i-1],l[i],l[i+1]) in s2:
            ans.append(2)
        else:
            ans.append(0)
    return ans
if N <= 20:
    for _ in range(N):
        A = calc(A)
    print(A[0])
    exit()
else:
    for _ in range(15):
        A = calc(A)
    n = len(A) //2
    if A[n-1] == 0 and A[n] == 0 and A[n + 1] == 0:
        print(0)
    else:
        print(A[-1])