#!/usr/bin/env python3 from bisect import bisect_left, bisect_right from collections import deque from itertools import permutations from sys import setrecursionlimit dpos4 = ((1, 0), (0, 1), (-1, 0), (0, -1)) dpos8 = ((0, -1), (1, -1), (1, 0), (1, 1), (0, 1), (-1, 1), (-1, 0), (-1, -1)) mod1 = 10**9 + 7 mod2 = 998244353 inf = 1 << 60 def main(): N = int(input()) edges = [[] for _ in range(N)] for _ in range(N - 1): u, v = map(int, input().split()) u -= 1 v -= 1 edges[u].append(v) edges[v].append(u) dp1 = [True] * N dp2 = [True] * N setrecursionlimit(10**6) def dfs1(fr, prev=-1): val = False for to in edges[fr]: if to == prev: continue dfs1(to, fr) val |= dp1[to] dp1[fr] = not val def dfs2(fr, prev=-1): val = False for to in edges[fr]: val |= dp1[to] dp2[fr] = not val L = len(edges[fr]) lval = [False] * (L + 1) rval = [False] * (L + 1) for i in range(L): to = edges[fr][i] lval[i + 1] = lval[i] or dp1[to] j = L - 1 - i to = edges[fr][j] rval[j] = rval[j + 1] or dp1[to] for i in range(L): to = edges[fr][i] if to == prev: continue dp1[fr] = not (lval[i] or rval[i + 1]) dfs2(to, fr) dfs1(0) dfs2(0) print(sum(dp2)) if sum(dp2): print(*(i + 1 for i in range(N) if dp2[i]), sep='\n') if __name__ == "__main__": main()