Test 3 is RTE
What can I optimise?

n=int(input())
dic={}
for i in range(n):
    team=input().split()
    for x in team:
        if x in dic:
            dic[x].extend((y for y in team if y!=x and y not in dic[x]))
        else:
            dic[x]=[y for y in team if y!=x]
names=sorted(dic.keys())
s='Isenbaev'
level = { s: 0 }
k = 1
frontier = [s]
while frontier:
    next = []
    for u in frontier:
        for v in dic[u]:
            if v not in level:
                level[v] = k
                next.append(v)
    frontier = next
    k += 1
print('\n'.join((x+' '+str(level.get(x, 'undefined')) for x in names)))

Edited by author 09.08.2016 16:37