from bisect import *

INF = 10 ** 9
def lis(x):
    dp = [INF] * (len(x) + 1)
    id = [0] * len(x)
    for i in range(len(x)):
        id[i] = bisect_left(dp, x[i])
        dp[bisect_left(dp, x[i])] = x[i]
    m = max(id)
    b = [0] * (m + 1)
    for i in range(len(x) - 1, -1, -1):
        if id[i] == m:
            b[m] = x[i]
            m -= 1
    return bisect_left(dp, INF), b
def lds(x):
    dp = [-INF] * (len(x) + 1)
    id = [0] * len(x)
    for i in range(len(x)):
        id[i] = bisect_left(dp, x[i]) - 1
        dp[bisect_left(dp, x[i]) - 1] = x[i]
    m = min(id)
    b = [0] * (max(id) + 1)
    for i in range(len(x))[::-1]:
        if id[i] == m:
            b[m] = x[i]
            m += 1
    return dp[::-1].index(-INF), b

n = int(input())
p = list(map(int, input().split()))
leng, lis_min = lis(p)
_, lis_max = lds(p[::-1])
lis_max = lis_max[::-1][:leng][::-1]
ans2 = []
for i in range(len(lis_min)):
    if lis_min[i] == lis_max[i]: ans2.append(lis_min[i])
print(len(ans2))
print(*ans2)