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

DP = [0 for i in range(n)]
DP[0] = DP[1] = 1
for i in range(1, n):
    if A[i] == A[i - 1]:
        DP[i] = max(DP[i], DP[i - 1] + 1)
    if i > 1:
        DP[i] = max(DP[i], DP[i - 2] + 1)
print(DP[n - 1])