Problem p03660 (python)

Fixed submission:
from heapq import heappush,heappop,heapify
from collections import deque,defaultdict,Counter
import itertools
from itertools import permutations,combinations,groupby
import sys
import bisect
import string
import math
import time
import random
def S_():
    return input()
def LS():
    return [i for i in input().split()]
def I():
    return int(input())
def MI():
    return map(int,input().split())
def LI():
    return [int(i) for i in input().split()]
def LI_():
    return [int(i)-1 for i in input().split()]
def NI(n):
    return [int(input()) for i in range(n)]
def NI_(n):
    return [int(input())-1 for i in range(n)]
def StoI():
    return [ord(i)-97 for i in input()]
def ItoS(nn):
    return chr(nn+97)
def LtoS(ls):
    return ''.join([chr(i+97) for i in ls])
def GI(V,E,Directed=False,index=0):
    org_inp=[]
    g=[[] for i in range(n)]
    for i in range(E):
        inp=LI()
        org_inp.append(inp)
        if index==0:
            inp[0]-=1
            inp[1]-=1
        if len(inp)==2:
            a,b=inp
            g[a].append(b)
            if not Directed:
                g[b].append(a)
        elif len(inp)==3:
            a,b,c=inp
            aa=(inp[0],inp[2])
            bb=(inp[1],inp[2])
            g[a].append(bb)
            if not Directed:
                g[b].append(aa)
    return g,org_inp
def bit_combination(k,n=2):
    rt=[]
    for tb in range(n**k):
        s=[tb//(n**bt)%n for bt in range(k)]
        rt+=[s]
    return rt
def show(*inp,end='\n'):
    if show_flg:
        print(*inp,end=end)
YN=['Yes','No']
mo=10**9+7
inf=float('inf')
l_alp=string.ascii_lowercase
u_alp=string.ascii_uppercase
ts=time.time()
sys.setrecursionlimit(10**5)
input=lambda: sys.stdin.readline().rstrip()

def ran_input():
    import random
    n=random.randint(4,16)
    rmin,rmax=1,10
    a=[random.randint(rmin,rmax) for _ in range(n)]
    return n,a

show_flg=False
show_flg=True


ans=0

n=I()
g,c=GI(n,n-1)


v=[-1]*n
v[0]=1
v[n-1]=0

def dfs(x,s):
    r=[]
    for i in x:
        for nb in g[i]:
            if v[nb]==-1:
                r.append(nb)
                v[nb]=s
    return r

F=[0]
S=[n-1]
while F or S:
    F=dfs(F,1)
#    show('F',v,F,S)
    S=dfs(S,0)
#    show('S',v,F,S)

if sum(v)>n//2:
    ans='Fennec'
else:
    ans='Snuke'
    
print(ans)

Buggy submission (verdict: Runtime Error):
from collections import deque
n=int(input())
a=[0]*(n+1)
b=[0]*(n+1)
g=[[] for _ in range(n+1)]
for i in range(1,n):
    a[i],b[i]=map(int,input().split())
    g[a[i]].append(b[i])
    g[b[i]].append(a[i])

def bfs(x):
    cnt=0
    q=deque()
    q.append(x)
    vst=set()
    while len(q)>0:
        c=q.popleft()
        vst.add(c)
        for nb in g[c]:
            if nb not in vst:
                q.append(nb)
    return vst

def dfs(x,y,path,vst):
    path=deque(path)
    vst=deque(vst)
    path.append(x)
    vst.append(x)
    if x==y:
        return path
    
    for i in g[x]:
        if i not in vst:
            a=dfs(i,y,path,vst)
            if a!=None:
                return a

r=dfs(1,n,deque(),deque())
rl=list(r)
t=(len(rl)-1)//2
g[rl[t]].remove(rl[t+1])
#print(rl)

print('Fennec' if len(bfs(1))>=n//2 else 'Snuke')