import bisect
n = int(input())
P = list(map(int,input().split()))
inf = 10**10
min_lis = [inf]*(n+1)
min_id = []

def lis(P):
    dp = [inf]*(n+1)
    id = []
    for i,p in enumerate(P):
        ind = bisect.bisect_left(dp,p)
        dp[ind] = p
        id.append(ind)

    m = max(id)
    ans = []

    for i in range(n)[::-1]:
        if id[i] == m:
            ans.append(P[i])
            m -= 1

    return ans[::-1]

ans_min = lis(P)
ans_max = lis([-p for p in P][::-1])
ans_max = [-p for p in ans_max][::-1]

ans = []
for mi,ma in zip(ans_min,ans_max):
    if mi == ma:
        ans.append(mi)

print(len(ans))
print(*ans)