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 in Ruby (2.3.3) (judge verdict: Wrong Answer)

require 'set'
N, *rest = $stdin.read.split.map(&:to_i)
EDGES = Hash.new{|h, k| h[k] = [] } 
rest.each_slice(2){|a, b| EDGES[a] << b; EDGES[b] << a}

def find_path
  visited = Array.new(N+1)
  q = [[1, []]]
  visited[1] = true
  loop do
    pos, route = q.shift
    return route + [pos] if pos == N
    EDGES[pos].each do |newpos|
      next if visited[newpos]
      visited[newpos] = true
      q << [newpos, route + [pos]]
    end
  end
end

def calc_score(start, obst)
  score = 0
  visited = Array.new(N+1)
  q = [start]
  until q.empty?
    pos = q.shift
    score += 1
    EDGES[pos].each do |newpos|
      next if newpos == obst || visited[newpos]
      visited[newpos] = true
      q << newpos
    end
  end
  return score
end

path = find_path
scores = path.map{|pos|
  start = (EDGES[pos] - path).first
  calc_score(start, pos)
}

a = b = 0
x = 0; y = scores.length-1
next_player = nil
loop do
  a += scores[x]
  b += scores[y]
  if x + 1 == y
    next_player = 0
    break
  else
    x += 1
    if x + 1 == y
      next_player = 1
      break
    else
      y -= 1
    end
  end
end

p a: a, b: b, next_player: next_player if $DEBUG
if (next_player == 0 && a > b) || (next_player == 1 && a >= b)
  puts "Fennec"
else
  puts "Snuke"
end