N=int(input())
EDGE=[tuple(map(int,input().split())) for i in range(N)]

E=[[] for i in range(N+1)]

for x,y in EDGE:
    E[x].append(y)
    E[y].append(x)

Q=[(1,N+5)]
USE=[0]*(N+1)
FR=[-1]*(N+1)
USE[1]=1

while Q:
    x,fr=Q.pop()
    ANS=-1

    for to in E[x]:
        if fr==to:
            continue
        if USE[to]==0:
            USE[to]=1
            FR[to]=x
            Q.append((to,x))
        else:
            ANS=to
            NOW=x
            break
    if ANS!=-1:
        break

LIST0=[]
LIST1=[]

while NOW!=1:
    LIST0.append(NOW)
    NOW=FR[NOW]

while ANS!=1:
    LIST1.append(ANS)
    ANS=FR[ANS]

LIST0.append(1)
LIST1.append(1)

while LIST0[-1]==LIST1[-1]:
    x=LIST0.pop()
    y=LIST1.pop()

LIST=[x]+LIST0[::-1]+LIST1

SET=set()
for i in range(len(LIST)):
    x=LIST[i-1]
    y=LIST[i]
    SET.add((x,y))
    SET.add((y,x))

ALIST=[]
for i in range(N):
    if EDGE[i] in SET:
        ALIST.append(i+1)

print(len(ALIST))
print(*ALIST)