Buggy python submission (verdict: Time Limit Exceeded):
#!/usr/bin/env python3

import sys
# import time
# import math
# import numpy as np
# import scipy.sparse.csgraph as cs            # csgraph_from_dense(ndarray, null_value=inf), bellman_ford(G, return_predecessors=True), dijkstra, floyd_warshall
# import random                                # random, uniform, randint, randrange, shuffle, sample
# import string                                # ascii_lowercase, ascii_uppercase, ascii_letters, digits, hexdigits
# import re                                    # re.compile(pattern) => ptn obj; p.search(s), p.match(s), p.finditer(s) => match obj; p.sub(after, s)
# from bisect import bisect_left, bisect_right # bisect_left(a, x, lo=0, hi=len(a)) returns i such that all(val<x for val in a[lo:i]) and all(val>-=x for val in a[i:hi]).
from collections import deque                # deque class. deque(L): dq.append(x), dq.appendleft(x), dq.pop(), dq.popleft(), dq.rotate()
# from collections import defaultdict          # subclass of dict. defaultdict(facroty)
# from collections import Counter              # subclass of dict. Counter(iter): c.elements(), c.most_common(n), c.subtract(iter)
# from datetime import date, datetime          # date.today(), date(year,month,day) => date obj; datetime.now(), datetime(year,month,day,hour,second,microsecond) => datetime obj; subtraction => timedelta obj
# from datetime.datetime import strptime       # strptime('2019/01/01 10:05:20', '%Y/%m/%d/ %H:%M:%S') returns datetime obj
# from datetime import timedelta               # td.days, td.seconds, td.microseconds, td.total_seconds(). abs function is also available.
# from copy import copy, deepcopy              # use deepcopy to copy multi-dimentional matrix without reference
# from functools import reduce                 # reduce(f, iter[, init])
# from functools import lru_cache              # @lrucache ...arguments of functions should be able to be keys of dict (e.g. list is not allowed)
# from heapq import heapify, heappush, heappop # built-in list. heapify(L) changes list in-place to min-heap in O(n), heappush(heapL, x) and heappop(heapL) in O(lgn).
# from heapq import nlargest, nsmallest        # nlargest(n, iter[, key]) returns k-largest-list in O(n+klgn).
# from itertools import count, cycle, repeat   # count(start[,step]), cycle(iter), repeat(elm[,n])
# from itertools import groupby                # [(k, list(g)) for k, g in groupby('000112')] returns [('0',['0','0','0']), ('1',['1','1']), ('2',['2'])]
# from itertools import starmap                # starmap(pow, [[2,5], [3,2]]) returns [32, 9]
# from itertools import product, permutations  # product(iter, repeat=n), permutations(iter[,r])
# from itertools import combinations, combinations_with_replacement
# from itertools import accumulate             # accumulate(iter[, f])
# from operator import itemgetter              # itemgetter(1), itemgetter('key')
# from fractions import gcd                    # for Python 3.4 (previous contest @AtCoder)



def main():
    mod = 1000000007                # 10^9+7
    inf = float('inf')              # sys.float_info.max = 1.79...e+308
    # inf = 2 ** 64 - 1             # (for fast JIT compile in PyPy) 1.84...e+19
    sys.setrecursionlimit(10**6)    # 1000 -> 1000000
    def input(): return sys.stdin.readline().rstrip()
    def ii():    return int(input())
    def mi():    return map(int, input().split())
    def mi_0():  return map(lambda x: int(x)-1, input().split())
    def lmi():   return list(map(int, input().split()))
    def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))
    def li():    return list(input())


    def calc_dist_path_in_bfs(adj, start, goal):
        q = deque()
        q.append([[start], 0])
        while q:
            path, dist = q.popleft()
            u = path[-1]
            if u == goal:
                return dist, path
            if not visited[u]:
                visited[u] = True
                for v in adj[u]:
                    if not visited[v]:
                        tmp = path[:]
                        tmp.append(v)
                        q.append([tmp, dist+1])
    
    def calc_node_in_dfs(adj, start):
        cnt = 1
        stack = [start]
        visited[start] = True
        while stack:
            # print(stack)
            u = stack[-1]
            for v in adj[u]:
                if not visited[v]:
                    stack.append(v)
                    visited[v] = True
                    cnt += 1                  
                    break
            else:
                stack.pop()
        return cnt


    n = ii()
    adj = [[] for _ in range(n)]
    for _ in range(n-1):
        a, b = mi_0()
        adj[a].append(b)
        adj[b].append(a)
    
    visited = [False] * n
    dist, path = calc_dist_path_in_bfs(adj, start=0, goal=n-1)
    # print(dist)
    # print(path)
    
    visited = [False] * n
    if dist % 2 == 1:
        i = path[(dist-1)//2]
        j = path[(dist-1)//2 + 1]
        adj[i].remove(j)
        adj[j].remove(i)
        # i 彩色数 > j 彩色数 で Fennec 勝ち
        i_color = calc_node_in_dfs(adj, i)
        j_color = calc_node_in_dfs(adj, j)
        print('Fennec') if i_color > j_color else print('Snuke')
    else:
        i = path[dist//2]
        j = path[dist//2+1]
        adj[i].remove(j)
        adj[j].remove(i)
        # i 彩色数 >= j 彩色数 で Fennec 勝ち
        i_color = calc_node_in_dfs(adj, i)
        j_color = calc_node_in_dfs(adj, j)
        print('Fennec') if i_color >= j_color else print('Snuke')


if __name__ == "__main__":
    main()


Fixed submission:
#!/usr/bin/env python3

import sys
# import time
# import math
# import numpy as np
# import scipy.sparse.csgraph as cs            # csgraph_from_dense(ndarray, null_value=inf), bellman_ford(G, return_predecessors=True), dijkstra, floyd_warshall
# import random                                # random, uniform, randint, randrange, shuffle, sample
# import string                                # ascii_lowercase, ascii_uppercase, ascii_letters, digits, hexdigits
# import re                                    # re.compile(pattern) => ptn obj; p.search(s), p.match(s), p.finditer(s) => match obj; p.sub(after, s)
# from bisect import bisect_left, bisect_right # bisect_left(a, x, lo=0, hi=len(a)) returns i such that all(val<x for val in a[lo:i]) and all(val>-=x for val in a[i:hi]).
from collections import deque                # deque class. deque(L): dq.append(x), dq.appendleft(x), dq.pop(), dq.popleft(), dq.rotate()
# from collections import defaultdict          # subclass of dict. defaultdict(facroty)
# from collections import Counter              # subclass of dict. Counter(iter): c.elements(), c.most_common(n), c.subtract(iter)
# from datetime import date, datetime          # date.today(), date(year,month,day) => date obj; datetime.now(), datetime(year,month,day,hour,second,microsecond) => datetime obj; subtraction => timedelta obj
# from datetime.datetime import strptime       # strptime('2019/01/01 10:05:20', '%Y/%m/%d/ %H:%M:%S') returns datetime obj
# from datetime import timedelta               # td.days, td.seconds, td.microseconds, td.total_seconds(). abs function is also available.
# from copy import copy, deepcopy              # use deepcopy to copy multi-dimentional matrix without reference
# from functools import reduce                 # reduce(f, iter[, init])
# from functools import lru_cache              # @lrucache ...arguments of functions should be able to be keys of dict (e.g. list is not allowed)
# from heapq import heapify, heappush, heappop # built-in list. heapify(L) changes list in-place to min-heap in O(n), heappush(heapL, x) and heappop(heapL) in O(lgn).
# from heapq import nlargest, nsmallest        # nlargest(n, iter[, key]) returns k-largest-list in O(n+klgn).
# from itertools import count, cycle, repeat   # count(start[,step]), cycle(iter), repeat(elm[,n])
# from itertools import groupby                # [(k, list(g)) for k, g in groupby('000112')] returns [('0',['0','0','0']), ('1',['1','1']), ('2',['2'])]
# from itertools import starmap                # starmap(pow, [[2,5], [3,2]]) returns [32, 9]
# from itertools import product, permutations  # product(iter, repeat=n), permutations(iter[,r])
# from itertools import combinations, combinations_with_replacement
# from itertools import accumulate             # accumulate(iter[, f])
# from operator import itemgetter              # itemgetter(1), itemgetter('key')
# from fractions import gcd                    # for Python 3.4 (previous contest @AtCoder)



def main():
    mod = 1000000007                # 10^9+7
    inf = float('inf')              # sys.float_info.max = 1.79...e+308
    # inf = 2 ** 64 - 1             # (for fast JIT compile in PyPy) 1.84...e+19
    sys.setrecursionlimit(10**6)    # 1000 -> 1000000
    def input(): return sys.stdin.readline().rstrip()
    def ii():    return int(input())
    def mi():    return map(int, input().split())
    def mi_0():  return map(lambda x: int(x)-1, input().split())
    def lmi():   return list(map(int, input().split()))
    def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))
    def li():    return list(input())


    def restore_path(seq, start, goal):
        buf = []
        current = goal
        while current != start:
            buf.append(current)
            current = seq[current]
        buf.append(start)
        buf.reverse()
        return buf


    def calc_dist_path_in_bfs(adj, start, goal):
        q = deque()
        q.append([[start, None], 0])
        prev_memo = [None] * n
        while q:
            (u, prev), dist = q.popleft()
            if u == goal:
                prev_memo[u] = prev
                return dist, restore_path(prev_memo, start, goal)
            if not visited[u]:
                visited[u] = True
                prev_memo[u] = prev
                for v in adj[u]:
                    if not visited[v]:
                        q.append([[v, u], dist+1])
    
    def calc_node_in_dfs(adj, start):
        cnt = 1
        stack = [start]
        visited[start] = True
        while stack:
            # print(stack)
            u = stack[-1]
            for v in adj[u]:
                if not visited[v]:
                    stack.append(v)
                    visited[v] = True
                    cnt += 1                  
                    break
            else:
                stack.pop()
        return cnt


    n = ii()
    adj = [[] for _ in range(n)]
    for _ in range(n-1):
        a, b = mi_0()
        adj[a].append(b)
        adj[b].append(a)
    
    visited = [False] * n
    dist, path = calc_dist_path_in_bfs(adj, start=0, goal=n-1)
    # print(dist)
    # print(path)
    
    visited = [False] * n
    if dist % 2 == 1:
        i = path[(dist-1)//2]
        j = path[(dist-1)//2 + 1]
        adj[i].remove(j)
        adj[j].remove(i)
        # i 彩色数 > j 彩色数 で Fennec 勝ち
        i_color = calc_node_in_dfs(adj, i)
        j_color = calc_node_in_dfs(adj, j)
        print('Fennec') if i_color > j_color else print('Snuke')
    else:
        i = path[dist//2]
        j = path[dist//2+1]
        adj[i].remove(j)
        adj[j].remove(i)
        # i 彩色数 >= j 彩色数 で Fennec 勝ち
        i_color = calc_node_in_dfs(adj, i)
        j_color = calc_node_in_dfs(adj, j)
        print('Fennec') if i_color >= j_color else print('Snuke')


if __name__ == "__main__":
    main()