a, b = map(int, input().split())
A = set()
B = set()
for i in range(a):
    now = int(input())
    A.add(now)
for i in range(b):
    now = int(input())
    B.add(now)

f = A & B
print(len(f))
print(*sorted(f))
s = A - B
print(len(s))
print(*sorted(s))
t = B - A
print(len(t))
print(*sorted(t))