def main():
    N = int(input())
    *A, = map(int, input().split())
    DP = [[0]*N for i in range(N)]
    order = sorted(range(N), key=lambda x: A[x], reverse=True)

    for i in order:
        DP[i][i] = 1
        for j in range(i-1, -1, -1):
            DP[i][j] = DP[i][j+1]
            if A[i] < A[j]:
                DP[i][j] = max(DP[i][j], DP[j][i-1]+1)
        for j in range(i+1, N):
            DP[i][j] = DP[i][j-1]
            if A[i] < A[j]:
                DP[i][j] = max(DP[i][j], DP[j][i+1]+1)

    print(max(map(max, DP)))


if __name__ == '__main__':
    main()