Problem: Iahubina is tired of so many complicated languages, so she decided to invent a new, simple language. She already made a dictionary consisting of n 3-words. A 3-word is a sequence of exactly 3 lowercase letters of the first 24 letters of the English alphabet (a to x). She decided that some of the letters are vowels, and all the others are consonants. The whole language is based on a simple rule: any word that contains at least one vowel is correct.

Iahubina forgot which letters are the vowels, and wants to find some possible correct sets of vowels. She asks Iahub questions. In each question, she will give Iahub a set of letters considered vowels (in this question). For each question she wants to know how many words of the dictionary are correct, considering the given set of vowels.

Iahubina wants to know the xor of the squared answers to all the possible questions. There are 224 different questions, they are all subsets of the set of the first 24 letters of the English alphabet. Help Iahub find that number.

Input

The first line contains one integer, n (1 ≤ n ≤ 104). Each of the next n lines contains a 3-word consisting of 3 lowercase letters. There will be no two identical 3-words.

Output

Print one number, the xor of the squared answers to the queries.

Examples

Input

5
abc
aaa
ada
bcd
def


Output

0

Solution (in JAVA):

Solution:
import java.io.*;
import java.math.BigInteger;
import java.util.*;

import static java.lang.Double.parseDouble;
import static java.lang.Integer.MAX_VALUE;
import static java.lang.Integer.parseInt;
import static java.lang.Long.parseLong;

public class Main {
    public static void main(String[] args) throws IOException {
        new Solver().run();
    }
}

class Solver {
    BufferedReader in;
    PrintWriter out;
    StringTokenizer tok;

    void run() throws IOException {
        in = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);
        //in = new BufferedReader(new FileReader("people.in"));
        //PrintWriter out = new PrintWriter(new File("people.out"));
        solve();
        out.close();
    }

    int[] sum = new int[1 << 24];
    int[] cnt = new int[1 << 24];

    public void solve() throws IOException {

        int n = nextInt();
        for (int i = 0; i < n; ++i) {
            String s = next();
            int mask = 0;
            for (int j = 0; j < 3; ++j) {
                mask |= 1 << (s.charAt(j) - 'a');
            }
            ++cnt[mask];
        }
        solve(0, 24);
        int ans = 0;
        for (int i = 0; i < 1 << 24; ++i) {
            int c = sum[i];
            c = n - c;
            ans ^= (c * c);
        }
        out.println(ans);
    }

    void solve(int s, int k) {
        if (k == 0) {
            sum[s] = cnt[s];
            return;
        }
        int half = 1 << (k - 1);
        int mid = s + half;
        solve(s, k - 1);
        solve(mid, k - 1);
        int r = mid + half;
        for (int i = mid; i < r; ++i) {
            sum[i] += sum[i - half];
        }
    }

    String next() throws IOException {
        if (tok == null || !tok.hasMoreTokens()) {
            tok = new StringTokenizer(in.readLine());
        }
        return tok.nextToken();
    }

    BigInteger nextBigInteger() throws IOException {
        return new BigInteger(next());
    }

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

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

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