from bisect import bisect_left

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

def f(P):
    bef = [-1] * n
    lis = [0] * n
    lst = []
    pos = []
    for i, p in enumerate(P):
        j = bisect_left(lst, p)
        if len(lst) == j:
            lst.append(p)
            pos.append(i)
        else:
            lst[j] = p
            pos[j] = i
        lis[i] = j
        if j != 0:
            bef[i] = pos[j - 1]
    
    p = pos[-1]
    left = []
    while p != -1:
        left.append(P[p])
        p = bef[p]
    return left

left = f(P)[::-1]
P = P[::-1]
P = [-p for p in P]
right = f(P)
right = [-p for p in right]
ans = [l for l, r in zip(left, right) if l == r]
print(len(ans))
print(*ans)