5
1 2 3
2 4 5
3 -1 -1
4 -1 -1
5 -1 -1

1 2 4 5 3

import sys
sys.setrecursionlimit(10000)
n=int(input())
tree={}
for _ in range(n):
    parts=list(map(int,input().split()))
    tree[parts[0]]=(parts[1],parts[2])
result=[]
def preorder(node):
    if node==-1: return
    result.append(node)
    preorder(tree[node][0])
    preorder(tree[node][1])
preorder(1)
print(*result)