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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Globalization;
using System.Diagnostics;
using static System.Console;
using Pair = System.Collections.Generic.KeyValuePair<int, int>;
//using System.Numerics;

struct Edge : IComparable
{
    public int to, cost;
    public Edge(int to, int cost)
    {
        this.to = to;
        this.cost = cost;
    }
    public int CompareTo(object obj)
    {
        return cost - ((Edge)obj).cost;
    }
}

class Program
{
    static void Main()
    {
        //SetOut(new StreamWriter(OpenStandardOutput()) { AutoFlush = false });
        new Program().Solve();
        Out.Flush();
    }
    Scanner cin = new Scanner();
    Random rnd = new Random();
    Stopwatch sw = new Stopwatch();
    readonly int[] dd = { 0, 1, 0, -1, 0 };
    readonly int mod = 1000000007;
    readonly string alfa = "abcdefghijklmnopqrstuvwxyz";

    int N;
    List<int>[] H;
    int[] B;
    void Solve()
    {
        N = cin.Nextint;
        H = Enumerable.Range(0, N).Select(i => new List<int>()).ToArray();
        for (int i = 0; i < N - 1; i++)
        {
            int a = cin.Nextint - 1;
            int b = cin.Nextint - 1;
            H[a].Add(b);
            H[b].Add(a);
        }
        B = new int[N];
        B[0] = 1;
        B[N - 1] = -1;


        //0からの距離
        var D = Enumerable.Repeat(int.MaxValue, N).ToArray();
        D[0] = 0;
        var Q = new PriorityQueue<Edge>();
        Q.Enqueue(new Edge(0, 0));

        while (Q.Any())
        {
            var e = Q.Dequeue();
            var v = e.to;

            if (D[v] < -e.cost) continue;

            foreach (var gv in H[v])
            {
                if (D[gv] > D[v] + 1)
                {
                    D[gv] = D[v] + 1;
                    Q.Enqueue(new Edge(gv, -D[gv]));
                }
            }

        }

        var E = Enumerable.Repeat(int.MaxValue, N).ToArray();
        E[N - 1] = 0;
        Q = new PriorityQueue<Edge>();
        Q.Enqueue(new Edge(N - 1, 0));

        while (Q.Any())
        {
            var e = Q.Dequeue();
            var v = e.to;

            if (E[v] < -e.cost) continue;

            foreach (var gv in H[v])
            {
                if (E[gv] > E[v] + 1)
                {
                    E[gv] = E[v] + 1;
                    Q.Enqueue(new Edge(gv, -E[gv]));
                }
            }

        }

        var F = new PriorityQueue<Edge>();
        foreach (var item in H[0])
        {
            if (B[item] == 0) F.Enqueue(new Edge(item, -E[item]));
        }
        var S = new PriorityQueue<Edge>();
        foreach (var item in H[N - 1])
        {
            if (B[item] == 0) S.Enqueue(new Edge(item, -D[item]));
        }

        while (true)
        {
            //F turn;
            bool flag = true;
            Edge f;
            while (F.Any())
            {
                f = F.Dequeue();
                if (B[f.to] == 0)
                {
                    flag = false;
                    B[f.to] = 1;
                    foreach (var item in H[f.to])
                    {
                        if (B[item] == 0) F.Enqueue(new Edge(item, -E[item]));
                    }

                    break;
                }
            }
            if(flag)
            {
                WriteLine("Snuke");
                break;
            }

            //S turn;
            flag = true;
            Edge s;
            while (S.Any())
            {
                s = S.Dequeue();
                if (B[s.to] == 0)
                {
                    flag = false;
                    B[s.to] = -1;
                    foreach (var item in H[s.to])
                    {
                        if (B[item] == 0) S.Enqueue(new Edge(item, -D[item]));
                    }
                    break;
                }
            }
            if (flag)
            {
                WriteLine("Fennec");
                break;
            }
        }

    }

}

class PriorityQueue<T> where T : IComparable
{
    List<T> heap;
    int size;
    int Compare(T x, T y) { return y.CompareTo(x); }
    public PriorityQueue() { heap = new List<T>(); }

    public void Enqueue(T x)
    {
        heap.Add(x);
        int i = size++;

        while (i > 0)
        {
            int p = (i - 1) >> 1;

            if (Compare(heap[p], x) <= 0) break;

            heap[i] = heap[p];
            i = p;
        }
        heap[i] = x;
    }

    public T Dequeue()
    {
        T ret = heap[0];
        T x = heap[--size];

        int i = 0;
        while ((i << 1) + 1 < size)
        {
            int a = (i << 1) + 1;
            int b = (i << 1) + 2;

            if (b < size && Compare(heap[b], heap[a]) < 0)
                a = b;
            if (Compare(heap[a], x) >= 0)
                break;

            heap[i] = heap[a];
            i = a;
        }
        heap[i] = x;
        heap.RemoveAt(size);
        return ret;
    }

    public int Count { get { return size; } }

    public bool Any() { return size > 0; }

    public T Peek() { return heap[0]; }
}
class Scanner
{
    string[] s; int i;
    char[] cs = new char[] { ' ' };
    public Scanner() { s = new string[0]; i = 0; }
    public string[] Scan { get { return ReadLine().Split(); } }
    public int[] Scanint { get { return Array.ConvertAll(Scan, int.Parse); } }
    public long[] Scanlong { get { return Array.ConvertAll(Scan, long.Parse); } }
    public double[] Scandouble { get { return Array.ConvertAll(Scan, double.Parse); } }
    public string Next
    {
        get
        {
            if (i < s.Length) return s[i++];
            string st = ReadLine();
            while (st == "") st = ReadLine();
            s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
            i = 0;
            return Next;
        }
    }
    public int Nextint { get { return int.Parse(Next); } }
    public long Nextlong { get { return long.Parse(Next); } }
    public double Nextdouble { get { return double.Parse(Next); } }
}