from collections import deque

n = int(input())

g = [[] for _ in range(n)]
edges = []
for _ in range(n):
  a, b = map(int, input().split())
  a -= 1
  b -= 1
  g[a].append(b)
  g[b].append(a)
  edges.append((a, b))

dq = deque()
deg = [len(g[v]) for v in range(n)]
used = [False for _ in range(n)]
for v in range(n):
	if deg[v] == 1:
		deg[v] -= 1
		used[v] = True
		dq.appendleft(v)

while len(dq) > 0:
	cur = dq.pop()
	for nxt in g[cur]:
		if used[nxt]:
			continue
		deg[nxt] -= 1
		if deg[nxt] == 1:
			deg[nxt] -= 1
			used[nxt] = True
			dq.appendleft(nxt)

print(used)
ans = []
for i in range(len(edges)):
	a, b = edges[i]
	if not used[a] and not used[b]:
	  ans.append(i + 1)

print(len(ans))
print(*ans, sep=" ")