#!/usr/local/bin/python3

sta = 'yamada'
b = [('suzuki', 'satou'), ('yamada', 'tanaka'), ('tanaka', 'satou'), ('watanabe', 'suzuki')]

ans = []
nodes = {}
for x, y in b:
    nodes.setdefault(x, []).append(y)
    nodes.setdefault(y, []).append(x)
has_run = set()

num_person = len(set(sum(b)))

baton_holder = sta

for _ in range(num_person):
    ans.append(baton_holder)
    has_run.add(baton_holder)
    candidates = nodes[baton_holder]
    for baton_holder in candidates:
        if baton_holder not in has_run: break

print(ans)