N = int(input())
A = list(map(int,input().split()))
DP = [[0] * 2 for _ in range(N)]
DP[0][1] = 1
for i in range(1,N):
    DP[i][0] = max(DP[i-1][0], DP[i-1][1])
    if A[i-1] == A[i]:
        DP[i][1] = max(DP[i-1][0] + 1, DP[i-1][1] + 1)
    else:
        DP[i][1] = max(DP[i-1][0] + 1, DP[i-1][1])
print(max(DP[-1]))