import sys

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N = int(readline())
m = map(int, read().split())

G = [[] for _ in range(N + 1)]
for a, b in zip(m, m):
    G[a].append(b)
    G[b].append(a)

root = 1
parent = [0] * (N + 1)
order = []
stack = [root]
while stack:
    x = stack.pop()
    order.append(x)
    for y in G[x]:
        if y == parent[x]:
            continue
        parent[y] = x
        stack.append(y)

dp_v = [[0, 0] for _ in range(N + 1)]
dp_e_d = [False] * (N + 1)

for v in order[::-1]:
    p = parent[v]
    if dp_v[v][0] == 0:
        dp_e_d[v] = True
        dp_v[p][0] += 1
    else:
        dp_v[p][1] += 1

dp_e_u = [False] * (N + 1)
for v in order:
    if v == root:
        continue
    p = parent[v]
    dp_e_u[v] = dp_v[p][0] - (dp_e_d[v]) == 0
    if dp_e_u[v]:
        dp_v[v][0] += 1
    else:
        dp_v[v][1] += 1

win_v = [v for v in range(1, N + 1) if not dp_v[v][0]]

print(len(win_v))
print('\n'.join(map(str, win_v)))