Problem:
Score : 300 points

Problem Statement

Snuke has N hats. The i-th hat has an integer a_i written on it.

There are N camels standing in a circle.
Snuke will put one of his hats on each of these camels.

If there exists a way to distribute the hats to the camels such that the following condition is satisfied for every camel, print Yes; otherwise, print No.

The bitwise XOR of the numbers written on the hats on both adjacent camels is equal to the number on the hat on itself.

What is XOR?

The bitwise XOR x_1 \oplus x_2 \oplus \ldots \oplus x_n of n non-negative integers x_1, x_2, \ldots, x_n is defined as follows:

- When x_1 \oplus x_2 \oplus \ldots \oplus x_n is written in base two, the digit in the 2^k's place (k \geq 0) is 1 if the number of integers among x_1, x_2, \ldots, x_n whose binary representations have 1 in the 2^k's place is odd, and 0 if that count is even.

For example, 3 \oplus 5 = 6.

Constraints

All values in input are integers.

3 \leq N \leq 10^{5}

0 \leq a_i \leq 10^{9}

Input

Input is given from Standard Input in the following format:

N
a_1 a_2 \ldots a_{N}

Output

Print the answer.

Sample Input 1

3
1 2 3

Sample Output 1

Yes

If we put the hats with 1, 2, and 3 in this order, clockwise, the condition will be satisfied for every camel, so the answer is Yes.

Sample Input 2

4
1 2 4 8

Sample Output 2

No

There is no such way to distribute the hats; the answer is No.

Solution in C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization.Formatters.Binary;
#if !DEBUG
    using System.IO;
#endif


public class Program {
    public static void Main() {
        #region SetAutoFlushIsFalse
#if !DEBUG
        var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
        Console.SetOut(sw);
#endif
        #endregion
        var n = ReadLib.ReadAsInt();
        var aArr = ReadLib.ReadAsIntArray();
        var isOk = Calculation.Calc(n, aArr);
        Console.WriteLine(isOk ? "Yes" : "No");
        #region Flush
#if !DEBUG
        Console.Out.Flush();
        sw.Close();
#endif
        #endregion
    }
}


static class Calculation {
    internal static bool Calc(int n, int[] aArr) {
        var dict = MyMethod.CountUp(aArr);

        var prevA = aArr[0];
        var currentA = aArr[1];

        dict[prevA] -= 1;
        dict[currentA] -= 1;

        for (int i = 1; i < n - 1; i++) {
            var cand = prevA ^ currentA;
            if (!dict.ContainsKey(cand) || dict[cand] == 0) {
                return false;
            }
            dict[cand] -= 1;

            prevA = currentA;
            currentA = cand;
        }

        return ((prevA ^ currentA) == aArr[0]) && ((currentA ^ aArr[0]) == aArr[1]);
    }
}


static class RootedTreeNodesFactory {
    public class RootedTreeNode {
        public int Id { get; }
        public int Parent { get; }
        public int Depth { get; set; }
        int[] Childs { get; }

        public RootedTreeNode(int id, int parent, int[] childs) {
            this.Id = id;
            this.Parent = parent;
            this.Childs = childs;
        }
    }
}


static class Quick {

    internal static void Calculate(int[] ts) {
        QuickSort(ts, 0, ts.Count() - 1);
    }

    private static void QuickSort(int[] ts, int p, int r) {
        if (p < r) {
            var q = Partition(ts, p, r);
            QuickSort(ts, p, q - 1);
            QuickSort(ts, q + 1, r);
        }
    }

    public static int Partition(int[] sArr, int p, int r) {
        var x = sArr[r];
        var i = p - 1;
        for (int j = p; j < r; j++) {
            if (sArr[j] <= x) {
                i++;
                sArr.Swap(i, j);
            }
        }
        sArr.Swap(i + 1, r);
        return i + 1;
    }

}

static class ReadLib {
    public static long ReadAsLong() {
        return long.Parse(Console.ReadLine());
    }

    public static int ReadAsInt() {
        return int.Parse(Console.ReadLine());
    }

    public static int[] ReadAsIntArray(int step = 0) {
        return Console.ReadLine().Split(' ').Select(s => int.Parse(s) + step).ToArray();
    }

    public static long[] ReadAsLongArray(int step = 0) {
        return Console.ReadLine().Split(' ').Select(s => long.Parse(s) + step).ToArray();
    }

    public static ulong[] ReadAsULongArray() {
        return Console.ReadLine().Split(' ').Select(s => ulong.Parse(s)).ToArray();
    }

    public static string[] ReadAsStringArray() {
        return Console.ReadLine().Split(' ');
    }

    public static int[] ReadNTimesAsInt(int n, int step = 0) {
        return Enumerable.Range(1, n).Select(s => int.Parse(Console.ReadLine()) + step).ToArray();
    }

    public static int[][] ReadNTimesAsIntArray(int n, int step = 0) {
        return Enumerable.Range(1, n).Select(s => ReadAsIntArray(step)).ToArray();
    }

    public static string[] ReadNTimesAsString(int n) {
        return Enumerable.Range(1, n).Select(s => Console.ReadLine()).ToArray();
    }

}

static class WriteLib {
    public static void Write<T>(IEnumerable<T> ts) {
        ts.ToList().ForEach(s => Console.WriteLine(s));
    }
}

static class MyMath {
    /// <summary>階乗</summary>
    public static long Factorial(int n) {
        if (n == 0) {
            return 1;
        }

        return Permutation(n, 0);
    }

    public static long Permutation(int n, int k) {
        return Enumerable.Range(0, n - k).Select(i => n - i).Aggregate(1, (b, i) => b * i);
    }

    #region FullPower
    /// <summary>総乗、π</summary>
    public static long FullPower(IEnumerable<long> vs) {
        return vs.Aggregate(1L, (a, b) => a * b);
    }

    public static long FullPower(IEnumerable<int> vs) {
        return vs.Aggregate(1L, (a, b) => a * b);
    }
    #endregion

    /// <summary>最大公約数</summary>
    public static long Gcd(long item1, long item2) {
        var a = Math.Max(item1, item2);
        var b = Math.Min(item1, item2);

        while (true) {
            long mod;
            Math.DivRem(a, b, out mod);
            if (mod == 0) {
                break;
            }

            a = b;
            b = mod;
        }
        return b;
    }

    /// <summary>約分。最大公約数で割ったものを返す。</summary>
    public static Tuple<long, long> DeviedByGcd(long item1, long item2) {
        var gcd = Gcd(item1, item2);
        return new Tuple<long, long>(item1 / gcd, item2 / gcd);
    }

    public static long Lcm(int item1, int item2) {
        return Math.BigMul(item1, item2) / Gcd(item1, item2);
    }

    public static ModCombination ModCombination(int maxN, int mod = 1000000007) {
        return new ModCombination(maxN, mod);
    }

    /// <summary>a^n mod</summary>
    public static int ModPow(int a, int n, int mod = 1000000007) {
        var res = 1;
        while (n > 0) {
            if ((n & 1) == 1) {
                res = (int)(Math.BigMul(res % mod, a) % mod);    // resにaをかける
            }
            a = (int)(Math.Pow(a % mod, 2) % mod);    // 次のaはa^2
            n >>= 1;
        }

        return res;
    }
}

static class MyMethod {
    /// <summary>数え上げて、key, 出現回数に変換</summary>
    public static Dictionary<T, int> CountUp<T>(IEnumerable<T> str) {
        return
            str
            .GroupBy(c => c)
            .Select(g => new KeyValuePair<T, int>(g.Key, g.Count()))
            .ToDictionary(e => e.Key, e => e.Value);
    }

    /// <summary>計数ソート</summary>
    public static int[] CountingSort(int[] aArr, int k) {
        int[] b, c;
        var n = aArr.Length;
        b = new int[n];
        c = Enumerable.Repeat(0, k + 1).ToArray();


        for (int i = 0; i < n; i++) {
            c[aArr[i]]++;
        }

        for (int i = 1; i <= k; i++) {
            c[i] += c[i - 1];
        }

        for (int i = n - 1; i >= 0; i--) {
            b[c[aArr[i]] - 1] = aArr[i];
            c[aArr[i]]--;
        }

        return b;
    }
}

/// <summary>無向グラフ</summary>
class UndirectedGraph {
    public Dictionary<int, List<int>> Graph { get; }

    /// <param name="graphArr">point1 to point2</param>
    /// <param name="n">グラフの全要素数</param>
    public UndirectedGraph(int[][] graphArr, int n) {
        Graph = new Dictionary<int, List<int>>();

        for (int i = 1; i <= n; i++) {
            Graph.Add(i, new List<int>());
        }

        foreach (var arr in graphArr) {
            Graph[arr[0]].Add(arr[1]);
            Graph[arr[1]].Add(arr[0]);
        }
    }
}
/// <summary>DeepCopyするクラス</summary>
class DeepCopier {
    BinaryFormatter b = new BinaryFormatter();
    public T DeepCopy<T>(T obj) {
        T result;
        using (var mem = new MemoryStream()) {
            b.Serialize(mem, obj); //  binaryFormatterによりobjをmemにserial化して書き出す
            mem.Position = 0; // memのpotisionを先頭に戻す
            result = (T)b.Deserialize(mem); // memの内容を読み取る。
        }
        return result;
    }
}

static class MergeSort {
    public static long[] Sort(long[] arr) {
        return Sort(arr, 0, arr.Count());
    }

    // rightは+1されていることに注意
    private static long[] Merge(long[] sArr, int left, int mid, int right) {
        var n1 = mid - left;
        var n2 = right - mid;

        var lArr = new long[n1 + 1];
        var rArr = new long[n2 + 1];

        for (int i = 0; i < n1; i++) {
            lArr[i] = sArr[left + i];
        }
        lArr[n1] = int.MaxValue;

        for (int i = 0; i < n2; i++) {
            rArr[i] = sArr[mid + i];
        }
        rArr[n2] = int.MaxValue;

        int l = 0, r = 0;
        for (int k = left; k < right; k++) {
            if (lArr[l] <= rArr[r]) {
                sArr[k] = lArr[l];
                l++;
            } else {
                sArr[k] = rArr[r];
                r++;
            }
        }
        return sArr; // 要素数はright - left
    }

    private static long[] Sort(long[] sArr, int left, int right) {
        if (left + 1 < right) {
            var mid = (left + right) / 2;
            sArr = Sort(sArr, left, mid);
            sArr = Sort(sArr, mid, right);
            sArr = Merge(sArr, left, mid, right);
        }
        return sArr;
    }
}

/// <summary>あまりを計算するためのintのラッパー</summary>
struct ModInt {
    int Value { get; }
    int Mod { get; }

    public override string ToString() {
        return Value.ToString();
    }

    public static explicit operator ModInt(long value) {
        return new ModInt(value);
    }

    public ModInt(long value, int mod = 1000000007) {
        this.Value = (int)(value % mod);
        this.Mod = mod;
    }

    public static explicit operator int(ModInt modInt) {
        return modInt.Value;
    }

    private static void CheckNotEqualMod(ModInt item1, ModInt item2) {
        if (item1.Mod != item2.Mod) {
            throw new Exception("mod not equal");
        }
    }

    public static ModInt operator +(ModInt item1, ModInt item2) {
        CheckNotEqualMod(item1, item2);
        long value = item1.Value + item2.Value;
        return new ModInt(value, item1.Mod);
    }

    public static ModInt operator *(ModInt item1, ModInt item2) {
        CheckNotEqualMod(item1, item2);
        long value = Math.BigMul(item1.Value, item2.Value);
        return new ModInt(value, item1.Mod);
    }

    public static ModInt operator -(ModInt item1, ModInt item2) {
        CheckNotEqualMod(item1, item2);
        long value = item1.Value - item2.Value;
        if (value < 0) {
            value += item1.Mod;
        }
        return new ModInt(value, item1.Mod);
    }

    public static ModInt operator +(ModInt item1, int item2) {
        return item1 + new ModInt(item2, item1.Mod);
    }

    public static ModInt operator *(ModInt item1, int item2) {
        return item1 * new ModInt(item2, item1.Mod);
    }

    public static ModInt operator -(ModInt item1, int item2) {
        return item1 - new ModInt(item2, item1.Mod);
    }


    public override int GetHashCode() {
        return this.Value;
    }

    public override bool Equals(object obj) {
        if (obj == null || this.GetType() != obj.GetType()) {
            return false;
        }

        var modIntObj = (ModInt)obj;
        return modIntObj.Value == this.Value;
    }

    public static bool operator ==(ModInt item1, ModInt item2) {
        return item1.Value == item2.Value;
    }

    public static bool operator !=(ModInt item1, ModInt item2) {
        return !(item1 == item2);
    }

    public static bool operator ==(ModInt item1, int item2) {
        return item1.Value == item2;
    }

    public static bool operator !=(ModInt item1, int item2) {
        return !(item1.Value == item2);
    }

    public static bool operator >=(ModInt item1, ModInt item2) {
        return item1.Value >= item2.Value;
    }

    public static bool operator <=(ModInt item1, ModInt item2) {
        return item1.Value <= item2.Value;
    }

    public static bool operator >=(ModInt item1, int item2) {
        return item1.Value >= item2;
    }

    public static bool operator <=(ModInt item1, int item2) {
        return item1.Value <= item2;
    }

    public static bool operator >(ModInt item1, ModInt item2) {
        return item1.Value > item2.Value;
    }

    public static bool operator <(ModInt item1, ModInt item2) {
        return item1.Value < item2.Value;
    }

    public static bool operator >(ModInt item1, int item2) {
        return item1.Value >= item2;
    }

    public static bool operator <(ModInt item1, int item2) {
        return item1.Value <= item2;
    }
}

/// <summary>組み合わせ</summary>
class ModCombination {
    private int mod;
    private int[] fac;
    private int[] finv;
    private int[] inv;

    public ModCombination(int max, int mod = 1000000007) {
        this.mod = mod;
        fac = new int[max]; // modが法のn!の列

        inv = new int[max]; // indexの逆元の列
        finv = new int[max]; // modを法とした、invの累積の累積

        fac[0] = 1; fac[1] = 1;
        finv[0] = 1; finv[1] = 1;
        inv[1] = 1;

        for (int i = 2; i < max; i++) {
            fac[i] = (int)(Math.BigMul(fac[i - 1], i) % mod);  // factorを求める
            var s = Math.BigMul(inv[mod % i], mod / i) % mod;
            inv[i] = (int)(mod - s);　 // iに対する逆元を求める
            finv[i] = (int)(Math.BigMul(finv[i - 1], inv[i]) % mod);
        }
    }
    /// <summary>nCk</summary>
    public int Calculation(int n, int k) {
        if (n < k) return 0;
        if (n < 0 || k < 0) return 0;

        return (int)(Math.BigMul(fac[n], (int)(Math.BigMul(finv[k], finv[n - k]) % mod)) % mod);
    }
}

/// <summary>拡張メソッドs</summary>
static class Extention {
    /// <summary>iとjを入れ替える</summary>
    public static void Swap<T>(this T[] arr, int i, int j) {
        var buf = arr[i];
        arr[i] = arr[j];
        arr[j] = buf;
    }

    /// <summary>
    /// partition。末尾sArr[r]を基準として、左に基準より小さい数、右に基準より大きい数が存在するように配列を並び替える。
    /// </summary>
    /// <param name="sArr"></param>
    /// <param name="p">partitionの先頭の添字</param>
    /// <param name="r">partitionの末尾の添字</param>
    /// <returns>partitionの基準が存在する添字</returns>
    public static int Partition(this int[] sArr, int p, int r) {
        var x = sArr[r];
        var i = p - 1;
        for (int j = p; j < r; j++) {
            if (sArr[j] <= x) {
                i++;
                sArr.Swap(i, j);
            }
        }
        sArr.Swap(i + 1, r);
        return i + 1;
    }

    /// <summary>深いコピーをする</summary>
    public static T DeepCopy<T>(this T obj) {
        T result;
        var b = new BinaryFormatter();
        using (var mem = new MemoryStream()) {
            b.Serialize(mem, obj); //  binaryFormatterによりobjをmemにserial化して書き出す
            mem.Position = 0; // memのpotisionを先頭に戻す
            result = (T)b.Deserialize(mem); // memの内容を読み取る。
        }
        return result;
    }
}