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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        Bit bit = new Bit();
        for (int i = 0; i < n; i++) {
            bit.shiftXOR(sc.nextInt());
        }
        System.out.println(bit.getValue());
    }
    
    static class Bit {
        static final int size = 1500000;
        static final long mask = (1 << 30) - 1; 
        long[] arr;
        
        public Bit() {
            arr = new long[size];
            arr[0] = 1; 
        }
        
        public void shiftXOR(int val) {
            int div = val / 30;
            int mod = val % 30;
            for (int i = size - 1; i - div >= 0; i--) {
                long tmp = arr[i - div];
                tmp <<= mod;
                if (i - div > 0) {
                    tmp |= (arr[i - div - 1] << mod) >> 30;
                }
                arr[i] ^= tmp;
            }
        }
        
        public int getValue() {
            int value = 0;
            for (int i = 0; i < size; i++) {
                for (int j = 0; j < 30; j++) {
                    if ((arr[i] & (1L << j)) != 0) {
                        value ^= i * 30 + j;
                    }
                }
            }
            return value;
        }
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        if (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}