from collections import deque

N = int(input())
T = [[] for _ in range(N)]
AB = [tuple(int(x) - 1 for x in input().split()) for _ in range(N - 1)]
for a, b in AB:
    T[a].append(b)
    T[b].append(a)

# dfs
dfs_order = []
d = deque([0])
nonvisited = [True] * N
nonvisited[0] = False
while d:
    v = d.pop()
    for x in T[v]:
        if nonvisited[x]:
            d.append(x)
            dfs_order.append((x, v))
            nonvisited[x] = False

# 子から親へ
dp0, dp1 = [0] * N, [0] * N
for child, v in reversed(dfs_order):
    if dp0[child] == len(T[child]) - 1:
        dp1[v] += 1
    else:
        dp0[v] += 1

# 親から子へ
win = set()
if not dp1[0]:
    win.add(0)
for child, v in dfs_order:
    if v in win:
        dp1[child] += 1
    if not dp1[child] and dp1[v] != 1:
        win.add(child)

print(len(win))
if win:
    print(*sorted(w + 1 for w in win), sep='\n')