People in the Tomskaya region like magic formulas very much. You can see some of them below.

Imagine you are given a sequence of positive integer numbers p1, p2, ..., pn. Lets write down some magic formulas:

<image><image>

Here, "mod" means the operation of taking the residue after dividing.

The expression <image> means applying the bitwise xor (excluding "OR") operation to integers x and y. The given operation exists in all modern programming languages. For example, in languages C++ and Java it is represented by "^", in Pascal — by "xor".

People in the Tomskaya region like magic formulas very much, but they don't like to calculate them! Therefore you are given the sequence p, calculate the value of Q.

Input

The first line of the input contains the only integer n (1 ≤ n ≤ 106). The next line contains n integers: p1, p2, ..., pn (0 ≤ pi ≤ 2·109).

Output

The only line of output should contain a single integer — the value of Q.

Examples

Input

3
1 2 3


Output

3
import java.io.*;
import java.util.*;


public class scratch_25 {
    static class Reader {
        static BufferedReader reader;
        static StringTokenizer tokenizer;

        /**
         * call this method to initialize reader for InputStream
         */
        static void init(InputStream input) {
            reader = new BufferedReader(
                    new InputStreamReader(input));
            tokenizer = new StringTokenizer("");
        }

        /**
         * get next word
         */
        static String next() throws IOException {
            while (!tokenizer.hasMoreTokens()) {
                //TODO add check for eof if necessary
                tokenizer = new StringTokenizer(
                        reader.readLine());
            }
            return tokenizer.nextToken();
        }

        static int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        static double nextDouble() throws IOException {
            return Double.parseDouble(next());
        }

        static long nextLong() throws IOException {
            return Long.parseLong(next());
        }
    }

    public static class Graph{
        public static class Vertex{
            HashMap<Integer,Integer> nb= new HashMap<>();     // for neighbours of each vertex
        }

        public static HashMap<Integer,Vertex> vt;   // for vertices(all)

        public Graph(){
            vt= new HashMap<>();
        }

        public static int numVer(){
            return vt.size();
        }

        public static boolean contVer(int ver){
            return vt.containsKey(ver);
        }

        public static void addVer(int ver){
            Vertex v= new Vertex();
            vt.put(ver,v);
        }

        public static int numEdg(){
            int count=0;
            ArrayList<Integer> vrtc= new ArrayList<>(vt.keySet());
            for (int i = 0; i <vrtc.size() ; i++) {
                count+=(vt.get(vrtc.get(i))).nb.size();
            }
            return count/2;
        }

        public static boolean contEdg(int ver1, int ver2){
            if(vt.get(ver1)==null || vt.get(ver2)==null){
                return false;
            }

            Vertex v= vt.get(ver1);
            if(v.nb.containsKey(ver2)){
                return true;
            }
            return false;
        }

        public static void addEdge(int ver1, int ver2, int weight){
            if(!vt.containsKey(ver1) || !vt.containsKey(ver2)){
                return;
            }
            Vertex v1= vt.get(ver1);
            Vertex v2= vt.get(ver2);
            v1.nb.put(ver2,weight);                                 // if previously there is an edge, then this replaces that edge
            v2.nb.put(ver1,weight);
        }

        public static void delEdge(int ver1, int ver2){

            if(!vt.containsKey(ver1) || !vt.containsKey(ver2)){
                return;
            }

            vt.get(ver1).nb.remove(ver2);
            vt.get(ver2).nb.remove(ver1);

        }

        public static void delVer(int ver){
            if(!vt.containsKey(ver)){
                return;
            }
            Vertex v1= vt.get(ver);
            ArrayList<Integer> arr= new ArrayList<>(v1.nb.keySet());
            for (int i = 0; i <arr.size() ; i++) {
                int s= arr.get(i);
                vt.get(s).nb.remove(ver);
            }
            vt.remove(ver);
        }

        public class Pair{
            int vname;
            ArrayList<Integer> psf= new ArrayList<>();       // path so far
            int dis;
            int col;
        }









        public HashMap<Integer,Integer> bfs(int src){
            HashMap<Integer, Boolean> prcd= new HashMap<>();    // jo jo ho chuke hain unke liye

            HashMap<Integer, Integer> ans= new HashMap<>();

            LinkedList<Pair> queue= new LinkedList<>();      // for bfs queue

            Pair strtp= new Pair();

            strtp.vname= src;

            ArrayList<Integer> ar= new ArrayList<>();
            ar.add(src);

            strtp.psf= ar;
            strtp.dis=0;

            queue.addLast(strtp);

            while(!queue.isEmpty()){

                Pair rp =  queue.removeFirst();

                if(prcd.containsKey(rp.vname)){
                    continue;
                }
                prcd.put(rp.vname,true);
                ans.put(rp.vname,rp.dis);

//                if(contEdg(rp.vname,dst)){
//                    return true;
//                }

                Vertex a= vt.get(rp.vname);
                ArrayList<Integer> arr= new ArrayList<>(a.nb.keySet());
                for (int i = 0; i <arr.size() ; i++) {
                    int s= arr.get(i);
                    if(!prcd.containsKey(s)){
                        Pair np = new Pair();
                        np.vname= s;
                        np.dis+=rp.dis+a.nb.get(s);
                        np.psf.addAll(rp.psf);
                        np.psf.add(s);
//                        np.psf.add(s);
//                         np.psf= rp.psf+" "+s;
                        queue.addLast(np);
                    }

                }
            }
            return ans;

            //   return false;
        }








        public HashMap<Integer,Integer> dfs(int src){
            HashMap<Integer, Boolean> prcd= new HashMap<>();    // jo jo ho chuke hain unke liye

            HashMap<Integer, Integer> ans= new HashMap<>();

            LinkedList<Pair> stack= new LinkedList<>();      // for bfs queue

            Pair strtp= new Pair();

            strtp.vname= src;

            ArrayList<Integer> ar= new ArrayList<>();
            ar.add(src);

            strtp.psf= ar;
            strtp.dis=0;

            stack.addFirst(strtp);

            while(!stack.isEmpty()){

                Pair rp =  stack.removeFirst();

                if(prcd.containsKey(rp.vname)){
                    continue;
                }
                prcd.put(rp.vname,true);
                ans.put(rp.vname,rp.dis);

//                if(contEdg(rp.vname,dst)){
//                    return true;
//                }

                Vertex a= vt.get(rp.vname);
                ArrayList<Integer> arr= new ArrayList<>(a.nb.keySet());
                for (int i = 0; i <arr.size() ; i++) {
                    int s= arr.get(i);
                    if(!prcd.containsKey(s)){
                        Pair np = new Pair();
                        np.vname= s;
                        np.dis+=rp.dis+a.nb.get(s);
                        np.psf.addAll(rp.psf);
                        np.psf.add(s);
//                        np.psf.add(s);
//                         np.psf= rp.psf+" "+s;
                        stack.addFirst(np);
                    }

                }
            }
            return ans;

            //   return false;
        }






        public boolean isCycle(){
            HashMap<Integer, Boolean> prcd= new HashMap<>();    // jo jo ho chuke hain unke liye

            //   HashMap<Integer, Integer> ans= new HashMap<>();

            LinkedList<Pair> queue= new LinkedList<>();      // for bfs queue



            ArrayList<Integer> keys = new ArrayList<>(vt.keySet());
            for (int i = 0; i <keys.size(); i++) {
                int cur= keys.get(i);
                if(prcd.containsKey(cur)){
                    continue;
                }

                Pair sp = new Pair();
                sp.vname= cur;
                ArrayList<Integer> as= new ArrayList<>();
                as.add(cur);
                sp.psf= as;

                queue.addLast(sp);

                while(!queue.isEmpty()){




                    Pair rp= queue.removeFirst();
                    if(prcd.containsKey(rp.vname)){
                        return true;
                    }

                    prcd.put(rp.vname,true);




                    Vertex v1= vt.get(rp.vname);
                    ArrayList<Integer> nbrs= new ArrayList<>(v1.nb.keySet());
                    for (int j = 0; j <nbrs.size() ; j++) {
                        int u= nbrs.get(j);
                        Pair np= new Pair();
                        np.vname= u;
                        queue.addLast(np);
                    }
                }

            }
            return false;
        }






        public  ArrayList<ArrayList<Integer>> genConnctdComp(){
            HashMap<Integer, Boolean> prcd= new HashMap<>();    // jo jo ho chuke hain unke liye

            ArrayList<ArrayList<Integer>> ans= new ArrayList<>();

            //   HashMap<Integer, Integer> ans= new HashMap<>();

            LinkedList<Pair> queue= new LinkedList<>();      // for bfs queue

            //  int con=-1;

            ArrayList<Integer> keys = new ArrayList<>(vt.keySet());
            for (int i = 0; i <keys.size(); i++) {
                int cur= keys.get(i);
                if(prcd.containsKey(cur)){
                    //return true;
                    continue;
                }
                ArrayList<Integer> fu= new ArrayList<>();
                fu.add(cur);


                Pair sp = new Pair();
                sp.vname= cur;
                ArrayList<Integer> as= new ArrayList<>();
                as.add(cur);
                sp.psf= as;

                queue.addLast(sp);

                while(!queue.isEmpty()){




                    Pair rp= queue.removeFirst();
                    if(prcd.containsKey(rp.vname)){
                        //return true;
                        continue;
                    }

                    prcd.put(rp.vname,true);
                    fu.add(cur);



                    Vertex v1= vt.get(rp.vname);
                    ArrayList<Integer> nbrs= new ArrayList<>();
                    for (int j = 0; j <nbrs.size() ; j++) {
                        int u= nbrs.get(j);
                        Pair np= new Pair();
                        np.vname= u;
                        queue.addLast(np);
                    }
                }
                ans.add(fu);

            }
            //return false;
            return ans;

        }

        public boolean isBip(int src){                       // only for connected graph

            HashMap<Integer,Integer> clr= new HashMap<>();
            // colors are 1 and -1


            LinkedList<Integer>q = new LinkedList<Integer>();
            clr.put(src,1);
            q.add(src);


            while(!q.isEmpty()){

                int u = q.getFirst();
                q.pop();

                ArrayList<Integer> arr= new ArrayList<>(vt.keySet());

                for (int i = 0; i <arr.size() ; ++i) {

                    int x= arr.get(i);

                    if(vt.get(u).nb.containsKey(x) && !clr.containsKey(x)){

                        if(clr.get(u)==1){
                            clr.put(x,-1);
                        }
                        else{
                            clr.put(x,1);
                        }
                        q.push(x);
                    }

                    else if(vt.get(u).nb.containsKey(x) && (clr.get(x)==clr.get(u))){
                        return false;
                    }

                }
            }
            return true;
        }

















        public static void printGr() {
            ArrayList<Integer> arr= new ArrayList<>(vt.keySet());
            for (int i = 0; i <arr.size() ; i++) {
                int ver= arr.get(i);
                Vertex v1= vt.get(ver);
                ArrayList<Integer> arr1= new ArrayList<>(v1.nb.keySet());
                for (int j = 0; j <arr1.size() ; j++) {
                    System.out.println(ver+"-"+arr1.get(j)+":"+v1.nb.get(arr1.get(j)));
                }

            }
        }
    }

    static class Cus implements Comparable<Cus>{
        int size;
        int mon;
        int num;
        public Cus(int size,int mon,int num){
            this.size=size;
            this.mon=mon;
            this.num=num;
        }
        @Override
        public int compareTo(Cus o){
            if(this.mon!=o.mon){
            return this.mon-o.mon;}

            else{
                return o.size-this.size;
            }

        }



    }

    static class Table implements Comparable<Table>{
        int size;
        int num;
        public Table(int size,int num){
            this.size=size;
            this.num=num;
        }
        @Override
        public int compareTo(Table o){
            return this.size-o.size;
        }


    }






    public static void main(String[] args)  throws IOException {
        Reader.init(System.in);
        BufferedWriter out = new BufferedWriter(new OutputStreamWriter(System.out));
       int n= Reader.nextInt();
       long arr[]= new long[n];
       long ans=0;

       for (int i = 0; i <n ; i++) {
            arr[i]= Reader.nextLong();
            ans=ans^arr[i];
        }

       long a[]= new long[n];
       a[0]=0;

        for (int i = 1; i <n ; i++) {
            a[i]=a[i-1]^(i);
        }


        for (int i = 1; i <=n ; i++) {

            long x= a[i-1];

            long g= (n/i)%2;

            long l= g*x;

             ans= ans^(l^a[n%i]);


        }
        System.out.println(ans);




        















        }


















      



    static long gcd(long a, long b)
    {
        if (a == 0)
            return b;
        return gcd(b % a, a);
    }

    // method to return LCM of two numbers
    static long lcm(long a, long b)
    {
        return (a*b)/gcd(a, b);
    }

    // Driver method

    static int partition(long arr[],long arr1[], int low, int high)
    {
        long pivot = arr[high];
        int i = (low-1); // index of smaller element
        for (int j=low; j<high; j++)
        {
            // If current element is smaller than the pivot
            if (arr[j] < pivot)
            {
                i++;

                // swap arr[i] and arr[j]
                long temp = arr[i];
                arr[i] = arr[j];
                arr[j] = temp;
                long temp1=arr1[i];
                arr1[i]=arr1[j];
                arr1[j]=temp1;

            }
        }

        // swap arr[i+1] and arr[high] (or pivot)
        long temp = arr[i+1];
        arr[i+1] = arr[high];
        arr[high] = temp;
        long temp1= arr1[i+1];
        arr1[i+1]=arr1[high];
        arr1[high]= temp1;

        return i+1;
    }


    /* The main function that implements QuickSort()
      arr[] --> Array to be sorted,
      low  --> Starting index,
      high  --> Ending index */
    static void sort(long arr[],long arr1[], int low, int high)
    {
        if (low < high)
        {
            /* pi is partitioning index, arr[pi] is
              now at right place */
            int pi = partition(arr,arr1, low, high);

            // Recursively sort elements before
            // partition and after partition
            sort(arr,arr1, low, pi-1);
            sort(arr,arr1, pi+1, high);
        }
    }







































































    public static ArrayList<Integer> Sieve(int n) {
        boolean arr[]= new boolean [n+1];
        Arrays.fill(arr,true);
        arr[0]=false;
        arr[1]=false;
        for (int i = 2; i*i <=n ; i++) {
            if(arr[i]==true){
                for (int j = 2; j <=n/i ; j++) {
                    int u= i*j;
                    arr[u]=false;
                }}
        }
        ArrayList<Integer> ans= new ArrayList<>();
        for (int i = 0; i <n+1 ; i++) {
            if(arr[i]){
                ans.add(i);
            }
        }
        return ans;










    }





}