Problem:
 Score : 400 points    Problem Statement Fennec and Snuke are playing a board game.  On the board, there are N cells numbered 1 through N , and N-1 roads, each connecting two cells. Cell a_i is adjacent to Cell b_i through the i -th road. Every cell can be reached from every other cell by repeatedly traveling to an adjacent cell. In terms of graph theory, the graph formed by the cells and the roads is a tree.  Initially, Cell 1 is painted black, and Cell N is painted white. The other cells are not yet colored.
Fennec (who goes first) and Snuke (who goes second) alternately paint an uncolored cell.
More specifically, each player performs the following action in her/his turn:   Fennec: selects an uncolored cell that is adjacent to a black cell, and paints it black .  Snuke: selects an uncolored cell that is adjacent to a white cell, and paints it white .   A player loses when she/he cannot paint a cell. Determine the winner of the game when Fennec and Snuke play optimally.      Constraints  2 \leq N \leq 10^5  1 \leq a_i, b_i \leq N  The given graph is a tree.         Input Input is given from Standard Input in the following format:  N  a_1  b_1  :  a_{N-1}  b_{N-1}       Output If Fennec wins, print Fennec ; if Snuke wins, print Snuke .        Sample Input 1 7
3 6
1 2
3 1
7 4
5 7
1 4      Sample Output 1 Fennec  For example, if Fennec first paints Cell 2 black, she will win regardless of Snuke's moves.       Sample Input 2 4
1 4
4 2
2 3      Sample Output 2 Snuke

Solution (Python):
def main(sample_file = ''):

    """ convenient functions
    
    
    
    
    
    """

    """convenient decorator
    
    
        
        
        
        
        
        
        
        
        
        
    """
    
    
    import sys
    sys.setrecursionlimit(10**7)
    from itertools import accumulate, combinations, permutations, product 
    
    from math import factorial, ceil, floor, sqrt
    def factorize(n):
        """return the factors of the Arg and count of each factor
        
        Args:
            n (long): number to be resolved into factors
        
        Returns:
            list of tuples: factorize(220) returns [(2, 2), (5, 1), (11, 1)]
        """
        fct = []  
        b, e = 2, 0  
        while b * b <= n:
            while n % b == 0:
                n = n // b
                e = e + 1
            if e > 0:
                fct.append((b, e))
            b, e = b + 1, 0
        if n > 1:
            fct.append((n, 1))
        return fct
    def combinations_count(n, r):   
        """Return the number of selecting r pieces of items from n kinds of items.
        
        Args:
            n (long): number
            r (long): number
        
        Raises:
            Exception: not defined when n or r is negative
        
        Returns:
            long: number
        """
        
        if n < 0 or r < 0:
            raise Exception('combinations_count(n, r) not defined when n or r is negative')
        if n - r < r: r = n - r
        if r < 0: return 0
        if r == 0: return 1
        if r == 1: return n
        numerator = [n - r + k + 1 for k in range(r)]
        denominator = [k + 1 for k in range(r)]
        for p in range(2,r+1):
            pivot = denominator[p - 1]
            if pivot > 1:
                offset = (n - r) % p
                for k in range(p-1,r,p):
                    numerator[k - offset] /= pivot
                    denominator[k] /= pivot
        result = 1
        for k in range(r):
            if numerator[k] > 1:
                result *= int(numerator[k])
        return result
    def combinations_with_replacement_count(n, r):
        """Return the number of selecting r pieces of items from n kinds of items allowing individual elements to be repeated more than once.
        
        Args:
            n (long): number
            r (long): number
        
        Raises:
            Exception: not defined when n or r is negative
        
        Returns:
            long: number
        """
        if n < 0 or r < 0:
            raise Exception('combinations_with_replacement_count(n, r) not defined when n or r is negative')
        elif n == 0:
            return 1
        else:
            return combinations_count(n + r - 1, r)
    from bisect import bisect_left, bisect_right
    from collections import deque, Counter, defaultdict 
    from heapq import heapify, heappop, heappush, heappushpop, heapreplace,nlargest,nsmallest 
    from copy import deepcopy, copy 
    import operator
    from operator import itemgetter 
    
    
    from functools import reduce, lru_cache
    def chmin(x, y):
        """change minimum
        if x > y, x = y and return (x, True).
        convenient when solving problems of dp[i]
        
        Args:
            x (long): current minimum value
            y (long): potential minimum value
        
        Returns:
            (x, bool): (x, True) when updated, else (x, False)
        """
        if x > y:
            x = y
            return (x, True)
        else:
            return (x, False)
    def chmax(x, y):
        """change maximum
        if x < y, x = y and return (x, True).
        convenient when solving problems of dp[i]
        
        Args:
            x (long): current maximum value
            y (long): potential maximum value
        
        Returns:
            (x, bool): (x, True) when updated, else (x, False)
        """
        if x < y:
            x = y
            return (x, True)
        else:
            return (x, False)

    from fractions import gcd 
    def gcds(numbers):
        return reduce(gcd, numbers)
    def lcm(x, y):
        return (x * y) // gcd(x, y)
    def lcms(numbers):
        return reduce(lcm, numbers, 1)
    def make_divisors(n, reversed=False):
        """create list of divisors
        
        Args:
            number (int): number from which list of divisors is created
            reversed (bool, optional): ascending order if False. Defaults to False.
        
        Returns:
            list: list of divisors
        """
        divisors = set()
        for i in range(1, int(n**0.5)+1):
            if n % i == 0:
                divisors.add(i)
                divisors.add(n//i)
        return sorted(list(divisors),reverse=reversed)
    
    
    
    INF = 10 ** 18
    MOD = 10 ** 9 + 7
    AtoZ = list('abcdefghijklmnopqrsruvwxyz') 
    modpow = lambda a, n, p = MOD: pow(a, n, p) 
    def modinv(a, p = MOD):
        
        
        return modpow(a, p-2, p)
    def modinv_list(n, p = MOD):
        if n <= 1:
            return [0,1][:n+1]
        else:
            inv_t = [0,1]
            for i in range(2, n+1):
                inv_t += [inv_t[p % i] * (p - int(p / i)) % p]
            return inv_t
    def modfactorial_list(n, p = MOD):
        if n == 0:
            return [1]
        else:
            l = [0] * (n+1)
            tmp = 1
            for i in range(1, n+1):
                tmp = tmp * i % p
                l[i] = tmp
            return l
    def modcomb(n, k, fac_list = [], p = MOD):
        
        
        from math import factorial
        if n < 0 or k < 0 or n < k: return 0
        if n == 0 or k == 0: return 1
        if len(fac_list) <= n:
            a = factorial(n) % p
            b = factorial(k) % p
            c = factorial(n-k) % p
        else:
            a = fac_list[n]
            b = fac_list[k]
            c = fac_list[n-k]
        return (a * modpow(b, p-2, p) * modpow(c, p-2, p)) % p
    def modadd(a, b, p = MOD):
        return (a + b) % MOD
    def modsub(a, b, p = MOD):
        return (a - b) % p
    def modmul(a, b, p = MOD):
        return ((a % p) * (b % p)) % p
    def moddiv(a, b, p = MOD):
        return modmul(a, modpow(b, p-2, p))

    class UnionFindTree:
        """union find tree class
        TODO: fix this description...
        how to use (example):
        >>  uf = UnionFindTree(N) 
        >>  if uf.find_root(a) == uf.find_root(b):
        >>      do something
        >>  else:
        >>      do something
        >>      uf.unite(a, b)
        """
        def __init__(self, N):
            self.root = [-1] * (N+1)
            self.rank   = [0]  * (N+1)
            self.connected_num = [1] * (N+1)
    
        def find_root(self,x):
            root = self.root
            while root[x] != -1:
                x = root[x]
            return x
    
        def unite(self,x,y):
            root = self.root
            rank = self.rank
            connected_num = self.connected_num
            find_root = self.find_root
    
            rx = find_root(x)
            ry = find_root(y)
            if rx != ry:
                if rank[rx] < rank[ry]:
                    root[rx] = ry
                    rx,ry = ry,rx
                else:
                    if rank[rx] == rank[ry]:
                        rank[rx] += 1
                    root[ry] = rx       
                connected_num[rx] += connected_num[ry]

    class SegTree:
        """
        ref: https://qiita.com/takayg1/items/c811bd07c21923d7ec69
        init(init_val, ide_ele): 配列init_valで初期化 O(N)
        update(k, x): k番目の値をxに更新 O(logN)
        query(l, r): 区間[l, r)をsegfuncしたものを返す O(logN)
        """
        def __init__(self, init_val, segfunc, ide_ele):
            """
            init_val: 配列の初期値
            segfunc: 区間にしたい操作
            ide_ele: 単位元
            n: 要素数
            num: n以上の最小の2のべき乗
            tree: セグメント木(1-index)
            """
            n = len(init_val)
            self.segfunc = segfunc
            self.ide_ele = ide_ele
            self.num = 1 << (n - 1).bit_length()
            self.tree = [ide_ele] * 2 * self.num
            
            for i in range(n):
                self.tree[self.num + i] = init_val[i]
            
            for i in range(self.num - 1, 0, -1):
                self.tree[i] = self.segfunc(self.tree[2 * i], self.tree[2 * i + 1])

        def update(self, k, x):
            """
            k番目の値をxに更新
            k: index(0-index)
            x: update value
            """
            k += self.num
            self.tree[k] = x
            while k > 1:
                self.tree[k >> 1] = self.segfunc(self.tree[k], self.tree[k ^ 1])
                k >>= 1

        def query(self, l, r):
            """
            [l, r)のsegfuncしたものを得る
            l: index(0-index)
            r: index(0-index)
            """
            res = self.ide_ele
            l += self.num
            r += self.num
            while l < r:
                if l & 1:
                    res = self.segfunc(res, self.tree[l])
                    l += 1
                if r & 1:
                    res = self.segfunc(res, self.tree[r - 1])
                l >>= 1
                r >>= 1
            return res

    
    
    
    
    
    
    
    

    def BellmanFord(N, M, ABC, vertex_start, vertex_end, value_if_inf = -1, find_shortest = False):
        """to calculate furthest or shortest length between vertex_start and vertex_end using BellmanFord algorithm
        
        Args:
            N (int): number of vertices
            M (int): number of edges
            ABC (list): [(ai, bi, ci) for _ in range(N)] where i-th edge is directed from vertex ai to vertex bi and the length is ci 
            vertex_start (int): start vertex. usually use 0.
            vertex_end (int): end vertex. usually use N-1.
            value_if_inf (int or string as you like, optional): value you want when the furthest (or shortest) distance is infinite (or -infinite). Defaults to -1.
            find_shortest (bool, optional): choose False to find furthest path. Defaults to False.
        
        Returns:
            int or string: normally int (but can be str if you set value_if_inf to str)
            
        Example:
                N, M, P = R()
                ABC = [R() for _ in range(M)]
                ABC = [(a-1, b-1, c-P) for a, b, c in ABC]
                print(BellmanFord(N, M, ABC, 0, N-1, value_if_inf = 'inf'))

        """

        def make_reachable_list(N, M, ABC, vertex_start, vertex_end):
            reachable_to_direct = defaultdict(list)
            reachable_from_direct = defaultdict(list)
            reachable_from_start = [False] * N
            reachable_to_end = [False] * N
            reachable_from_start[vertex_start] = True
            reachable_to_end[vertex_end] = True
            reachable_from_both_sides = [False] * N
            dfs_from_start = []
            dfs_to_end = []
            for a, b, c in ABC:
                reachable_to_direct[a].append(b)
                reachable_from_direct[b].append(a)
                if a == vertex_start:
                    dfs_from_start.append(b)
                    reachable_from_start[b] = True
                if b == vertex_end:
                    dfs_to_end.append(a)
                    reachable_to_end[a] = True
            while dfs_from_start:
                v = dfs_from_start.pop()
                for i in reachable_to_direct[v]:
                    if not reachable_from_start[i]:
                        reachable_from_start[i] = True
                        dfs_from_start.append(i)
            while dfs_to_end:
                v = dfs_to_end.pop()
                for i in reachable_from_direct[v]:
                    if not reachable_to_end[i]:
                        reachable_to_end[i] = True
                        dfs_to_end.append(i)
            for i in range(N):
                reachable_from_both_sides[i] = reachable_from_start[i] and reachable_to_end[i]
            return reachable_from_both_sides
        
        reachable_from_both_sides = make_reachable_list(N, M, ABC, vertex_start, vertex_end)
        
        if find_shortest:
            dist = [INF for i in range(N)]
        else:
            dist = [-INF for i in range(N)]
        
        dist[vertex_start] = 0
        for i in range(N):
            updated = False
            for a, b, c in ABC:
                if not reachable_from_both_sides[a]:
                    continue
                elif find_shortest:
                    update_condition = dist[a] + c < dist[b]
                else:
                    update_condition = dist[a] + c > dist[b]
                if dist[a] != INF and update_condition:
                    dist[b] = dist[a] + c
                    updated = True
                    if i == N-1:
                        return value_if_inf
            if not updated:
                break
        return dist[vertex_end]

    
    def warshall_floyd(number_vertex, XYD, shift_one_for_vertex=False):
        
        
        
        
        
        d = [[float("inf")]*number_vertex for i in range(number_vertex)]
        for x, y, dist in XYD:
            if shift_one_for_vertex:
                x = x - 1
                y = y - 1
            d[x][y] = dist
            d[y][x] = dist
        for i in range(number_vertex):
            d[i][i] = 0 
        for k in range(number_vertex):
            for i in range(number_vertex):
                for j in range(number_vertex):
                    d[i][j] = min(d[i][j],d[i][k] + d[k][j])
        return d


    """ initialize variables and set inputs
    
        
        
            
            
    
        
        
        
        
        
        
        
    
        
        
        
        
    
        
        
    """

    
    r = lambda: sys.stdin.readline().strip()
    r_int = lambda: int(r())
    r_float = lambda: float(r())
    R = lambda: list(map(int, r().split()))
    R_str = lambda: r().split()
    R_map = lambda: map(int, r().split())
    R_float = lambda: list(map(float, r().split()))
    R_tuple = lambda: tuple(map(int, r().split()))

    """ how to treat input
    
    
    
    
    
    
    
    """

    
    if sample_file:
        sys.stdin = open(sample_file)
        
    
    
    
    N = r_int()
    AB = [R() for _ in range(N-1)]
    tree = [[] for _ in range(N)]
    for a, b in AB:
        tree[a-1].append(b-1)
        tree[b-1].append(a-1)
    task = [0]
    arrived = [0] * N
    arrived[0] = 1
    parent_node = [0] * N
    while task:
        node = task.pop()
        for child in tree[node]:
            if arrived[child] == 0:
                arrived[child] = 1
                task.append(child)
                parent_node[child] = node
            if child == N-1:
                break
    node = N - 1
    way_cnt = 1
    way = [N-1]
    while True:
        node = parent_node[node]
        way_cnt += 1
        way.append(node)
        if node == 0:
            break
    way = list(reversed(way))

    kireme = way[(way_cnt-1)//2]
    kireme_ikenai = way[(len(way)-1)//2+1]
    
    task = [0]
    arrived = [0] * N
    arrived[0] = 1
    cnt = 1
    while task:
        node = task.pop()
        for child in tree[node]:
            if child == kireme_ikenai:
                continue
            else:
                if not arrived[child]:
                    cnt += 1
                    arrived[child] = 1
                    task.append(child)
    if cnt > N - cnt:
        print('Fennec')
    else:
        print('Snuke')
        

        
    
    
    

    
    
    


    
    
    

    """memo: how to use defaultdict of list
    
    Dic = defaultdict(list)
    
    Dic[x].append(y)
    
    for k, v in Dic.items():
    """
    
    """memo: how to solve binary problems
    
    >>> a = 5
    >>> bin_str_a = format(a, '
    >>> print(bin_str_a)
    0b0101 
    """
    
    """memo: how to solve the problem
    creating simple test/answer
    greed
    simple dp
    graph
    """

if __name__ == '__main__':
    main()

Solution (Python):
import sys,queue,math,copy,itertools,bisect,collections
from heapq import *

def main():
    sys.setrecursionlimit(10**7)
    INF = 10**18
    MOD = 10**9 + 7
    LI = lambda : [int(x) for x in sys.stdin.readline().split()]
    NI = lambda : int(sys.stdin.readline())

    N = NI()
    root = [[] for _ in range(N)]
    for _ in range(N-1):
        a,b = LI()
        root[a-1].append(b-1)
        root[b-1].append(a-1)

    node = [-1 for _ in range(N)]
    q = []
    q.append((0,0))
    node[0] = 0
    while q:
        u,num = q.pop()
        for v in root[u]:
            if node[v] < 0:
                node[v] = num+1
                if v == N-1:
                    q = []
                    break
                q.append((v,num+1))
    c = node[N-1]
    u = N-1
    pu = 0
    while c > (node[N-1])//2:
        for v in root[u]:
            if node[v] != c-1: continue
            pu = u
            u = v
            c -= 1
            break

    p = u
    node = [-1 for _ in range(N)]
    node[p] = 0
    node[pu] = 1
    cnt = [0,0]
    for i in range(2):
        if i == 0:
            q.append(p)
        else:
            q.append(pu)
        while q:
            u = q.pop()
            for v in root[u]:
                if node[v] < 0:
                    node[v] = i
                    q.append(v)
                    cnt[i] += 1
    if cnt[0] > cnt[1]:
        print('Fennec')
    else:
        print('Snuke')

if __name__ == '__main__':
    main()

Solution (Python):
from collections import deque
n = int(input())
e = [[] for i in range(n)]
for i in range(n-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    e[a].append(b)
    e[b].append(a)



def bfs(x):
    dis = [float("INF")]*n
    q = deque([])
    dis[x] = 0
    q.append((x,-1))
    while q:
        now,bef = q.popleft()
        for nex in e[now]:
            if nex != bef:
                dis[nex] = dis[now]+1
                q.append((nex,now))
    return dis

dis1 = bfs(0)
dis2 = bfs(n-1)
count = 0
for i in range(n):
    if dis1[i] <= dis2[i]:
        count += 1
    else:
        count -= 1
if count > 0:
    print("Fennec")
else:
    print("Snuke")

Solution (Python):
import sys
input=sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
n=int(input())
edges=[[] for i in range(n)]
for i in range(n-1):
    a,s=map(int,input().split())
    a-=1;s-=1
    edges[a].append(s);edges[s].append(a)

def bfs(pre,now):
    for  i in edges[now]:
        if i==pre:continue
        if i==n-1:return[n-1,now]
        v=bfs(now,i)
        if v:v.append(now);return v
l=bfs(-1,0)
ll=len(l)
snuke_last=-(-ll//2)
table=[-1]*n
def c(now,pre):
    if table[now]!=-1:return table[now]
    if len(edges[now])>1:
        table[now]=1+sum(c(i,now) for i in edges[now] if i!=pre)
        return table[now]
    table[now]=1
    return 1
l=l[::-1]

d=c(l[snuke_last],l[snuke_last-1])

print("Fennec") if n-d>d else print("Snuke")
"""
1
2
3
4
567
"""

Solution (Python):
import sys
stdin = sys.stdin
sys.setrecursionlimit(10**6)
ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
nn = lambda: list(stdin.readline().split())
ns = lambda: stdin.readline().rstrip()

import copy

n = ni()
g = [{} for _ in range(n)]

for i in range(n-1):
    a,b = na()
    a,b = a-1,b-1
    g[a][i] = b
    g[b][i] = a

dis = [float('inf')]*n
near = [-1]*n
gg = [copy.deepcopy(line) for line in g]

def dfs(v,start,depth):
    if dis[v] > depth:
        dis[v] = depth
        near[v] = start
    if not g[v]:
        return
    while g[v]:
        key,nv = g[v].popitem()
        g[nv].pop(key)
        dfs(nv,start,depth+1)

dfs(0,0,0)
g = gg
dfs(n-1,n-1,0)

print('Fennec' if 2*near.count(0) > n else 'Snuke')

Solution (Python):
import sys
sys.setrecursionlimit(10**6)
input = sys.stdin.readline

n = int(input())
path = [[] for _ in range(n)]
for i in range(n-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    path[a].append(b)
    path[b].append(a)
parent = [-1]*n
size = [1]*n
d = [0]*n
def dfs(now):
    for nxt in path[now]:
        if nxt != parent[now]:
            parent[nxt] = now
            d[nxt] = d[now] + 1
            size[now] += dfs(nxt)
    return size[now]
dfs(0)
cnt = 0
now = n-1
for i in range((d[n-1]+1)//2 - 1):
    now = parent[now]
if size[now] >= n - size[now]:
    print('Snuke')
else:
    print('Fennec')

Solution (Python):
import heapq
class Graph:
    def __init__(self,v,edgelist,w_v = None,directed = False):
        super().__init__()
        self.v = v
        self.w_e = [{} for _ in [0]*self.v]
        self.neighbor = [[] for _ in [0]*self.v]
        self.w_v = w_v
        self.directed = directed

        for i,j,w in edgelist:
            self.w_e[i][j] = w
            self.neighbor[i].append(j)

    def dijkstra(self,v_n):
        d = [float('inf')]*self.v
        d[v_n] = 0
        prev = [-1]*self.v

        queue = []
        for i,d_i in enumerate(d): heapq.heappush(queue,(d_i,i))
        
        while len(queue)>0:
            d_u,u = queue.pop()
            if d[u]<d_u :continue
            for v in self.neighbor[u]:
                alt = d[u]+self.w_e[u][v]
                if d[v]>alt:
                    d[v] = alt
                    prev[v] = u
                    heapq.heappush(queue,(alt,v))

        return d,prev

    def warshallFloyd(self):
        d = [[10**18]*self.v for _ in [0]*self.v]
        for i in range(self.v):
            d[i][i] = 0
            
        for i in range(self.v):
            for j in self.neighbor[i]:
                d[i][j] = self.w_e[i][j]
            
        for i in range(self.v):
            for j in self.neighbor[i]:
                d[i][j] = self.w_e[i][j]
        
        for k in range(self.v):
            for i in range(self.v):
                for j in range(self.v):
                    check = d[i][k] + d[k][j]
                    if d[i][j] > check:
                        d[i][j] = check
        return d

    def prim(self):
        gb = GraphBuilder(self.v,self.directed)

        queue = []
        for i,w in self.w_e[0].items(): heapq.heappush(queue,(w,0,i))
        rest = [True]*self.v
        rest[0] = False

        while len(queue)>0:
            w,i,j = heapq.heappop(queue)
            if rest[j]:
                gb.addEdge(i,j,w)
                rest[j] = False
                for k,w in self.w_e[j].items():
                    if rest[k]:
                        heapq.heappush(queue,(w,j,k))

        return gb


class Tree():
    def __init__(self,v,e):
        pass

class GraphBuilder():
    def __init__(self,v,directed = False):
        self.v = v
        self.directed = directed
        self.edge = []

    def addEdge(self,i,j,w=1):
        if not self.directed:
            self.edge.append((j,i,w))
        self.edge.append((i,j,w))

    def addEdges(self,edgelist,weight = True):
        if weight:
            if self.directed:
                for i,j,w in edgelist:
                    self.edge.append((i,j,w))
            else:
                for i,j,w in edgelist:
                    self.edge.append((i,j,w))
                    self.edge.append((j,i,w))
        else:
            if self.directed:
                for i,j in edgelist:
                    self.edge.append((i,j,1))
            else:
                for i,j in edgelist:
                    self.edge.append((i,j,1))
                    self.edge.append((j,i,1))
            

    def addAdjMat(self, mat):
        for i,mat_i in enumerate(mat):
            for j,w in enumerate(mat_i):
                self.edge.append((i,j,w))

    def buildTree(self):
        pass

    def buildGraph(self):
        return Graph(self.v,self.edge,directed=self.directed)

def main():
    n = int(input())
    
    edge = [tuple([int(t)-1 for t in input().split()])for _ in [0]*(n-1)]

    gb = GraphBuilder(n)
    gb.addEdges(edge,False)

    g = gb.buildGraph()

    node = [0]*n

    head = [0]
    tail = [n-1]
    
    while len(head)>0 or len(tail)>0:
        t = []
        while len(head)>0:
            h = head.pop()
            for i in g.neighbor[h]:
                if node[i]==0:
                    t.append(i)
                    node[i] = 1
        head = t

        t = []
        while len(tail)>0:
            h = tail.pop()
            for i in g.neighbor[h]:
                if node[i]==0:
                    t.append(i)
                    node[i] = -1
        tail = t

    ans = sum(node)
    if ans>0:
        print("Fennec")
    else:
        print("Snuke")

if __name__ == "__main__":
    main()

Solution (Python):
import heapq
 
"""
https://juppy.hatenablog.com/entry/2019/02/18/%E8%9F%BB%E6%9C%AC_python_%E3%83%97%E3%83%A9%E3%82%A4%E3%82%AA%E3%83%AA%E3%83%86%E3%82%A3%E3%82%AD%E3%83%A5%E3%83%BC%28heapq%29%E3%82%92%E7%94%A8%E3%81%84%E3%81%9F%E3%83%97%E3%83%AA%E3%83%A0%E6%B3%95
"""
 
def dijkstra_heap(s,edge):
    
    d = [10**10]*n
    used = [True] * n 
    d[s] = 0
    used[s] = False
    edgelist = []
    for a,b in edge[s]:
        heapq.heappush(edgelist,a*(10**6)+b)
    while len(edgelist):
        minedge = heapq.heappop(edgelist)
        
        if not used[minedge%(10**6)]:
            continue
        v = minedge%(10**6)
        d[v] = minedge//(10**6)
        used[v] = False
        for e in edge[v]:
            if used[e[1]]:
                heapq.heappush(edgelist,(e[0]+d[v])*(10**6)+e[1])
    return d
 

N = int(input())
n = N
w = N
 
edge = tuple([] for i in range(n))

for i in range(w-1):
    a,b = map(int,input().split())
    edge[a-1].append([1,b-1])
    edge[b-1].append([1,a-1])

dist_zero = dijkstra_heap(0,edge)
dist_n = dijkstra_heap(N-1,edge)
"""
print(dist_zero)
print(dist_n)
"""
b = 0
w = 0

for black,white in zip(dist_zero,dist_n):
    if black > white:
        w += 1
    else:
        b += 1

if b > w:
    print("Fennec")
else:
    print("Snuke")

Solution (Python):
import heapq
 
"""
https://juppy.hatenablog.com/entry/2019/02/18/%E8%9F%BB%E6%9C%AC_python_%E3%83%97%E3%83%A9%E3%82%A4%E3%82%AA%E3%83%AA%E3%83%86%E3%82%A3%E3%82%AD%E3%83%A5%E3%83%BC%28heapq%29%E3%82%92%E7%94%A8%E3%81%84%E3%81%9F%E3%83%97%E3%83%AA%E3%83%A0%E6%B3%95
"""
 
def dijkstra_heap(s,edge):
    
    d = [10**10]*n
    used = [True] * n 
    d[s] = 0
    used[s] = False
    edgelist = []
    for a,b in edge[s]:
        heapq.heappush(edgelist,a*(10**6)+b)
    while len(edgelist):
        minedge = heapq.heappop(edgelist)
        
        if not used[minedge%(10**6)]:
            continue
        v = minedge%(10**6)
        d[v] = minedge//(10**6)
        used[v] = False
        for e in edge[v]:
            if used[e[1]]:
                heapq.heappush(edgelist,(e[0]+d[v])*(10**6)+e[1])
    return d
 

N = int(input())
n = N
w = N
 
edge = tuple([] for i in range(n))

for i in range(w-1):
    a,b = map(int,input().split())
    edge[a-1].append([1,b-1])
    edge[b-1].append([1,a-1])

dist_zero = dijkstra_heap(0,edge)
dist_n = dijkstra_heap(N-1,edge)
"""
print(dist_zero)
print(dist_n)
"""
b = 0
w = 0

for black,white in zip(dist_zero,dist_n):
    if black > white:
        w += 1
    else:
        b += 1

if b > w:
    print("Fennec")
else:
    print("Snuke")

Solution (Python):
import sys
sys.setrecursionlimit(10**6)
    
def main():
    N = int(input())
    d = {}
    for _ in range(N-1):
        a, b = map(int, input().split())
        if a in d:
            d[a].append(b)
        else:
            d[a] = [b]
        if b in d:
            d[b].append(a)
        else:
            d[b] = [a]
    v = set()
    v.add(1)
    l = []
    def dfs(n):
        if n == N:
            l.append(n)
            return True
        for i in d[n]:
            if i not in v:
                v.add(i)
                if dfs(i):
                    l.append(n)
                    return True
        return False
    dfs(1)
    l.reverse()
    v = set()
    if len(l) % 2 == 0:
        half = len(l) // 2 - 1
    else:
        half = len(l) // 2
    v.add(l[half])
    s = l[half+1]
    v.add(s)
    def dfs2(n):
        r = 1
        for i in d[n]:
            if i not in v:
                v.add(i)
                r += dfs2(i)
        return r
    x = dfs2(s)
    if N - x > x:
        return 'Fennec'
    else:
        return 'Snuke'
print(main())

Solution (Python):
def main():
    N = int(input())
    E = [[] for _ in range(N)]
    for _ in range(N - 1):
        a, b = map(int, input().split())
        E[a - 1].append(b - 1)
        E[b - 1].append(a - 1)
    C = [0] * N
    B = set([0])
    W = set([N - 1])
    C[0] = 1
    C[-1] = -1
    while B or W:
        BN = set()
        for b in B:
            for bb in E[b]:
                if bb != b and C[bb] == 0:
                    C[bb] = 1
                    BN.add(bb)
        B = BN
        WN = set()
        for w in W:
            for ww in E[w]:
                if ww != w and C[ww] == 0:
                    C[ww] = -1
                    WN.add(ww)
        W = WN
    return 'Fennec' if C.count(1) > C.count(-1) else 'Snuke'

print(main())

Solution (Python):
import sys
sys.setrecursionlimit(10**6)
input=sys.stdin.readline
from collections import deque
N=int(input())

graph=[[] for _ in range(N+1)]
for _ in range(N-1):
  a,b=map(int,input().split())
  graph[a].append(b)
  graph[b].append(a)


dist_f=[-1]*(N+1)
d=0
queue=[1]
while queue:  
  new_queue=set()
  for u in queue:
    dist_f[u]=d
    for v in graph[u]:
      if dist_f[v]==-1:
        new_queue.add(v)
        
  queue=list(new_queue)
  d+=1


dist_s=[-1]*(N+1)
d=0
queue=[N]
while queue:  
  new_queue=set()
  for u in queue:
    dist_s[u]=d
    for v in graph[u]:
      if dist_s[v]==-1:
        new_queue.add(v)
        
  queue=list(new_queue)
  d+=1


cnt_f,cnt_s=0,0
for i in range(1,N+1):
  if dist_f[i]<=dist_s[i]:
    cnt_f+=1
  else:
    cnt_s+=1


if cnt_f>cnt_s:
  print("Fennec")
else:
  print("Snuke")