Problem: You are given n words, each of which consists of lowercase alphabet letters. Each word contains at least one vowel. You are going to choose some of the given words and make as many beautiful lyrics as possible.

Each lyric consists of two lines. Each line consists of two words separated by whitespace. 

A lyric is beautiful if and only if it satisfies all conditions below. 

  * The number of vowels in the first word of the first line is the same as the number of vowels in the first word of the second line. 
  * The number of vowels in the second word of the first line is the same as the number of vowels in the second word of the second line. 
  * The last vowel of the first line is the same as the last vowel of the second line. Note that there may be consonants after the vowel. 



Also, letters "a", "e", "o", "i", and "u" are vowels. Note that "y" is never vowel.

For example of a beautiful lyric, 

"hello hellooowww" 

"whatsup yowowowow" 

is a beautiful lyric because there are two vowels each in "hello" and "whatsup", four vowels each in "hellooowww" and "yowowowow" (keep in mind that "y" is not a vowel), and the last vowel of each line is "o".

For example of a not beautiful lyric, 

"hey man"

"iam mcdic" 

is not a beautiful lyric because "hey" and "iam" don't have same number of vowels and the last vowels of two lines are different ("a" in the first and "i" in the second).

How many beautiful lyrics can you write from given words? Note that you cannot use a word more times than it is given to you. For example, if a word is given three times, you can use it at most three times.

Input

The first line contains single integer n (1 ≤ n ≤ 10^{5}) — the number of words.

The i-th of the next n lines contains string s_{i} consisting lowercase alphabet letters — the i-th word. It is guaranteed that the sum of the total word length is equal or less than 10^{6}. Each word contains at least one vowel.

Output

In the first line, print m — the number of maximum possible beautiful lyrics.

In next 2m lines, print m beautiful lyrics (two lines per lyric).

If there are multiple answers, print any.

Examples

Input


14
wow
this
is
the
first
mcdics
codeforces
round
hooray
i
am
proud
about
that


Output


3
about proud
hooray round
wow first
this is
i that
mcdics am


Input


7
arsijo
suggested
the
idea
for
this
problem


Output


0


Input


4
same
same
same
differ


Output


1
same differ
same same

Note

In the first example, those beautiful lyrics are one of the possible answers. Let's look at the first lyric on the sample output of the first example. "about proud hooray round" forms a beautiful lyric because "about" and "hooray" have same number of vowels, "proud" and "round" have same number of vowels, and both lines have same last vowel. On the other hand, you cannot form any beautiful lyric with the word "codeforces".

In the second example, you cannot form any beautiful lyric from given words.

In the third example, you can use the word "same" up to three times.

Solution (in JAVA):

Solution:
import java.util.*;
import java.io.*;
import static java.lang.Math.*;
public class MainS {
    static final long MOD = 1_000_000_007, INF = 1_000_000_000_000_000_000L;
    static final int INf = 1_000_000_000;
    static FastReader reader;
    static PrintWriter writer;

    public static void main(String[] args) {
        Thread t = new Thread(null, new O(), "Integer.MAX_VALUE", 100000000);
        t.start();
    }

    static class O implements Runnable {
        public void run() {
            try {
                magic();
            } catch (Exception e) {
                e.printStackTrace();
                System.exit(1);
            }
        }
    }

    public static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

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

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

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

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

    }
    static int pos[];
    static LinkedList<Integer> list[][];
    static HashSet<Integer> counts;
    static int count_vowel[], last_vowel[];
    static String arr[];
    static void magic() throws IOException {
        reader = new FastReader();
        writer = new PrintWriter(System.out, true);
        pos = new int[26];
        Arrays.fill(pos, -1);
        pos['a'-'a'] = 0;
        pos['e'-'a'] = 1;
        pos['i'-'a'] = 2;
        pos['o'-'a'] = 3;
        pos['u'-'a'] = 4;
        counts = new HashSet<>();
        int n = reader.nextInt();
        count_vowel = new int[n];
        last_vowel = new int[n];
        arr = new String[n];
        list = new LinkedList[1000001][5];
        for(int i=0;i<n;++i) {
            String s = reader.next();
            int len = s.length();
            int cnt = 0, p = -1;
            for(int j=0;j<len;++j) {
                if(pos[s.charAt(j)-'a']!=-1) {
                    ++cnt;
                    p = pos[s.charAt(j)-'a'];
                }
            }
            count_vowel[i] = cnt;
            last_vowel[i] = p;
            counts.add(cnt);
            for(int j=0;j<5;++j) {
                list[cnt][j] = new LinkedList<>();
            }
            arr[i] = s;
        }
        for(int i=0;i<n;++i) {
            list[count_vowel[i]][last_vowel[i]].add(i);
        }
        int low = 0, high = n/4, mid, ans = low;
        while(low<=high) {
            mid = (low+high)>>1;
            if(check(mid)) {
                ans = mid;
                low = ++mid;
            }
            else {
                high = --mid;
            }
        }
        writer.println(ans);
        if(ans>0) {
            print(ans);
        }
    }
    static boolean check(int x) {
        int second_pair = 0, first_pair = 0;
        for(int e : counts) {
            int iska = 0;
            for(int i=0;i<5;++i) {
                if(second_pair>=x) {
                    iska+=list[e][i].size();
                }
                else {
                    int need = (x-second_pair);
                    int can_give = list[e][i].size()/2;
                    int taken = min(need, can_give);
                    second_pair+=taken;
                    iska+=(list[e][i].size() - taken*2);
                }
            }
            first_pair+=iska/2;
        }
        return second_pair>=x && first_pair>=x;
    }
    static void print(int x) {
        ArrayList<Integer> first_pairs = new ArrayList<>();
        ArrayList<Integer> second_pairs = new ArrayList<>();
        int second_pair = 0, first_pair = 0;
        for(int e : counts) {
            for(int i=0;i<5;++i) {
                int need = (x-second_pair);
                int can_give = list[e][i].size()/2;
                int taken = min(need, can_give);
                for(int j=0;j<taken;++j) {
                    second_pairs.add(list[e][i].pollFirst());
                    second_pairs.add(list[e][i].pollFirst());
                }
                second_pair+=taken;
                if(second_pair>=x) {
                    break;
                }
            }
        }
        for(int e:counts) {
            LinkedList<Integer> lol = new LinkedList<>();
            for(int i=0;i<5;++i) {
                for(int k : list[e][i]) {
                    lol.addLast(k);
                }
            }
            int need = (x-first_pair);
            int can_give = lol.size()/2;
            int taken = min(need, can_give);
            for(int j=0;j<taken;++j) {
                first_pairs.add(lol.pollFirst());
                first_pairs.add(lol.pollFirst());
            }
            first_pair+=taken;
            if(first_pair>=x) {
                break;
            }
        }
        StringBuilder fast = new StringBuilder();
        for(int i=0;i<first_pairs.size();i+=2) {
            fast.append(arr[first_pairs.get(i)]);
            fast.append(" ");
            fast.append(arr[second_pairs.get(i)]);
            fast.append("\n");
            fast.append(arr[first_pairs.get(i+1)]);
            fast.append(" ");
            fast.append(arr[second_pairs.get(i+1)]);
            fast.append("\n");
        }
        writer.print(fast);
        writer.flush();
    }
}