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.util.* ;
import java.io.* ;
import java.util.regex.* ;
import java.text.* ;
import java.math.* ;

public class Main {
	public static void main( String[] args ) {
		InputStream isObj ;
		OutputStream osObj ;
		InputReader irObj ;
		PrintWriter pwObj ;
		String inputFileName , outputFileName ;
		File fObj1 , fObj2 ;
		int T , ind ;
		boolean hasMoreInput , hasTestCases ;
		ProblemSolver psObj ;
		//only variable to be changed here is hasTestCases and osObj(optional for file output)
		hasTestCases = ProblemSolver.HAS_TEST_CASES ;
		isObj = System.in ;
		osObj = System.out ;
		inputFileName = ProblemSolver.INPUT_FILE_NAME ;
		outputFileName = ProblemSolver.OUTPUT_FILE_NAME ;
		try {
			fObj1 = new File( System.getProperty( "user.dir" ).toString() + "\\" + inputFileName ) ;
			fObj2 = new File( System.getProperty( "user.dir" ).toString() + "\\" + outputFileName ) ;
			if( fObj1.exists() == false ) {
				fObj1 = new File( System.getProperty( "user.dir" ).toString() + "\\src\\" + inputFileName ) ;
				fObj2 = new File( System.getProperty( "user.dir" ).toString() + "\\src\\" + outputFileName ) ;
			}
			isObj = new FileInputStream( fObj1 ) ;
			if( ProblemSolver.DO_OUTPUT_TO_FILE == true ) {
				osObj = new FileOutputStream( fObj2 ) ;
			}
		}
		catch( Exception ex ) {
			ex.printStackTrace() ;
			isObj = System.in ;
			osObj = System.out ;
		}
		irObj = new InputReader( isObj ) ;
		pwObj = new PrintWriter( osObj ) ;
		try {
			psObj = new ProblemSolver() ;
			if( hasTestCases == true ) {
				//for input with test cases
				T = irObj.nextInt() ;
				for( ind = 1 ; ind <= T ; ind++ ) {        	
					psObj.clearPerCase() ;
					psObj.getInput( irObj ) ;
					psObj.solveCase( pwObj ) ;
				}
			}
			else {
				//for end of file input
				for( ind = 1 ; ; ind++ ) {        	
					psObj.clearPerCase() ;
					hasMoreInput = psObj.getInput( irObj ) ;
					if( hasMoreInput == false ) {
						break ;
					}
					psObj.solveCase( pwObj ) ;
				}
			}
			pwObj.flush() ;
			isObj.close() ;
			osObj.close() ;
		}
		catch( Exception ex ) {
			ex.printStackTrace() ;
			throw new RuntimeException( ex ) ;
		}
		finally {
			pwObj.close() ;
		}
	}
}

class ProblemSolver {
	public static final boolean HAS_TEST_CASES = false ;
	public static final String INPUT_FILE_NAME = "test.in" ;
	public static final String OUTPUT_FILE_NAME = "out.txt" ;
	public static final boolean DO_OUTPUT_TO_FILE = false ;
	
	public void solveCase( PrintWriter pwObj ) {
		int i , j , a , c , b , d ;
		long res ;
		res = 0 ;
		this.lrr[ 0 ] = 0 ;
		for( i = 1 ; i < this.lim1 ; i++ ) {
			this.lrr[ i ] = ( long ) this.lrr[ i - 1 ] ^ ( long ) i ;
		}
		for( i = 0 ; i < this.n ; i++ ) {
			res ^= ( long ) this.arr[ i ] ;
		}
		for( i = 0 ; i < this.n ; i++ ) {
			a = ( this.n ) / ( i + 1 ) ;
			b = ( this.n ) % ( i + 1 ) ;
			if( a % 2 == 0 ) {
				res ^= this.lrr[ b ] ;
			}
			else {
				res ^= this.lrr[ b ] ;
				res ^= this.lrr[ i ] ;
			}
		}
		pwObj.println( res ) ;
	}
	
	private void init() {
		//default values
		this.lim1 = 1000010 ;
		this.lim2 = 110 ;
		this.cc = 1 ;
		this.ind = 0 ;
		this.declareArrays() ;
		this.fillAllArrays() ;
	}
	
	public boolean getInput( InputReader irObj ) {
		int i ;
		try {
			this.n = irObj.nextInt() ;
		}
		catch( Exception ex ) {
			return false ;
		}
		for( i = 0 ; i < this.n ; i++ ) {
			this.arr[ i ] = irObj.nextInt() ;			
		}
		return true ;
	}
	
	private int lim1 , lim2 , cn , ind , cc , n ; 
	private String[] srr ;
	private int[] arr , brr ;
	private Node[] nrr ;
	private long[] lrr ;
	private int[][] memo , done ;
	private ArrayList< Integer >[] adj_list ;
	
	public void clearPerCase() {
		this.incrementInd() ;
		this.incrementCc() ;
		this.n = 0 ;
		this.cn = 0 ;
		Arrays.fill( this.brr , 0 ) ;
	}
	
	private void declareArrays() {
		//array declarations
		this.arr = new int[ this.lim1 ] ;
		this.brr = new int[ this.lim1 ] ;
		this.lrr = new long[ this.lim1 ] ;
		this.srr = new String[ this.lim1 ] ;
		this.nrr = new Node[ this.lim1 ] ;
		this.memo = new int[ this.lim2 ][ this.lim2 ] ;
		this.done = new int[ this.lim2 ][ this.lim2 ] ;
		this.adj_list = new ArrayList[ this.lim1 ] ;
	}
	
	private void fillAllArrays() {
		int i ;
		//array initiations
		Arrays.fill( this.arr , 0 ) ;
		Arrays.fill( this.brr , 0 ) ;
		Arrays.fill( this.lrr , 0 ) ;
		for( int zrr[] : this.memo ) {
			Arrays.fill( zrr , -1 ) ;
		}
		for( int zrr[] : this.done ) {
			Arrays.fill( zrr , 0 ) ;
		}
		for( i = 0 ; i < this.lim1 ; i++ ) {
			this.srr[ i ] = new String( "" ) ;
			this.nrr[ i ] = new Node( Integer.MIN_VALUE , Integer.MIN_VALUE ) ;
			this.adj_list[ i ] = new ArrayList< Integer >() ;
		}
	}
	
	private void incrementInd() {
		this.ind++ ;
	}
	
	public void setCn( int c ) {
		this.cn = c ;  
	}
	
	public void incrementCn() {
		this.cn++ ;
	}
	
	public void incrementCc() {
		this.cc++ ;
	}
	
	public int getCn() {
		return this.cn ;
	}
	
	public ProblemSolver() {
		this.init() ;
	}
}

class Node implements Comparable< Node > {
	private int v , f ;
	
	private Node() {
	}
	
	public Node( int vParam , int fParam ) {
		this.v = vParam ;
		this.f = fParam ;
	}
	
	public void setV( int vParam ) {
		this.v = vParam ;
	}
	
	public void setF( int fParam ) {
		this.f = fParam ;
	}
	
	public int getV() {
		return this.v ;
	}
	
	public int getF() {
		return this.f ;
	}
	
	public int compareTo( Node nParam ) {
		return this.getV() - nParam.getV() ;
	}
}

class InputReader {
	private BufferedReader reader ;
	private StringTokenizer tokenizer ;

	public InputReader( InputStream stream ) {
		this.reader = new BufferedReader( new InputStreamReader( stream ) ) ;
		this.tokenizer = null ;
	}

	private String next( int fl ) {
		while( this.tokenizer == null || ! this.tokenizer.hasMoreTokens() ) {
			try {                
				this.tokenizer = new StringTokenizer( this.reader.readLine() ) ;
			}
			catch( IOException e ) {
				throw new RuntimeException( e ) ;
			}
		}
		String s ;
		s = "" ;
		if( fl == 1 ) {
			s = this.tokenizer.nextToken() ; 
		}
		return s ;
	}

	public String nextLine() {
		this.next( 0 ) ;
		int fl ;
		String line ;
		line = "" ;
		fl = 0 ;
		if( this.tokenizer != null ) {
			while( this.tokenizer.hasMoreTokens() ) {
				if( fl == 1 ) {
					line += " " ;
				}
				fl = 1 ;
				line += this.tokenizer.nextToken() ;
			}
		}
		return line ;
	}

	public int nextInt() {
		return Integer.parseInt( this.next( 1 ) ) ;
	}

	public long nextLong() {
		return Long.parseLong( this.next( 1 ) ) ;
	}

	public double nextDouble() {
		return Double.parseDouble( this.next( 1 ) ) ;
	}

	public String nextString() {
		return this.next( 1 ) ;
	}
}
