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 CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
long long int ceil(long long int a, long long int b) { return (a + b - 1) / b; }
const int base = 1000000000;
const int base_digits = 9;
struct bigint {
  vector<int> a;
  int sign;
  bigint() : sign(1) {}
  bigint(long long v) { *this = v; }
  bigint(const string &s) { read(s); }
  void operator=(const bigint &v) {
    sign = v.sign;
    a = v.a;
  }
  void operator=(long long v) {
    sign = 1;
    if (v < 0) sign = -1, v = -v;
    for (; v > 0; v = v / base) a.push_back(v % base);
  }
  bigint operator+(const bigint &v) const {
    if (sign == v.sign) {
      bigint res = v;
      for (int i = 0, carry = 0; i < (int)max(a.size(), v.a.size()) || carry;
           ++i) {
        if (i == (int)res.a.size()) res.a.push_back(0);
        res.a[i] += carry + (i < (int)a.size() ? a[i] : 0);
        carry = res.a[i] >= base;
        if (carry) res.a[i] -= base;
      }
      return res;
    }
    return *this - (-v);
  }
  bigint operator-(const bigint &v) const {
    if (sign == v.sign) {
      if (abs() >= v.abs()) {
        bigint res = *this;
        for (int i = 0, carry = 0; i < (int)v.a.size() || carry; ++i) {
          res.a[i] -= carry + (i < (int)v.a.size() ? v.a[i] : 0);
          carry = res.a[i] < 0;
          if (carry) res.a[i] += base;
        }
        res.trim();
        return res;
      }
      return -(v - *this);
    }
    return *this + (-v);
  }
  void operator*=(int v) {
    if (v < 0) sign = -sign, v = -v;
    for (int i = 0, carry = 0; i < (int)a.size() || carry; ++i) {
      if (i == (int)a.size()) a.push_back(0);
      long long cur = a[i] * (long long)v + carry;
      carry = (int)(cur / base);
      a[i] = (int)(cur % base);
    }
    trim();
  }
  bigint operator*(int v) const {
    bigint res = *this;
    res *= v;
    return res;
  }
  friend pair<bigint, bigint> divmod(const bigint &a1, const bigint &b1) {
    int norm = base / (b1.a.back() + 1);
    bigint a = a1.abs() * norm;
    bigint b = b1.abs() * norm;
    bigint q, r;
    q.a.resize(a.a.size());
    for (int i = a.a.size() - 1; i >= 0; i--) {
      r *= base;
      r += a.a[i];
      int s1 = r.a.size() <= b.a.size() ? 0 : r.a[b.a.size()];
      int s2 = r.a.size() <= b.a.size() - 1 ? 0 : r.a[b.a.size() - 1];
      int d = ((long long)base * s1 + s2) / b.a.back();
      r -= b * d;
      while (r < 0) r += b, --d;
      q.a[i] = d;
    }
    q.sign = a1.sign * b1.sign;
    r.sign = a1.sign;
    q.trim();
    r.trim();
    return make_pair(q, r / norm);
  }
  bigint operator/(const bigint &v) const { return divmod(*this, v).first; }
  bigint operator%(const bigint &v) const { return divmod(*this, v).second; }
  void operator/=(int v) {
    if (v < 0) sign = -sign, v = -v;
    for (int i = (int)a.size() - 1, rem = 0; i >= 0; --i) {
      long long cur = a[i] + rem * (long long)base;
      a[i] = (int)(cur / v);
      rem = (int)(cur % v);
    }
    trim();
  }
  bigint operator/(int v) const {
    bigint res = *this;
    res /= v;
    return res;
  }
  int operator%(int v) const {
    if (v < 0) v = -v;
    int m = 0;
    for (int i = a.size() - 1; i >= 0; --i)
      m = (a[i] + m * (long long)base) % v;
    return m * sign;
  }
  void operator+=(const bigint &v) { *this = *this + v; }
  void operator-=(const bigint &v) { *this = *this - v; }
  void operator*=(const bigint &v) { *this = *this * v; }
  void operator/=(const bigint &v) { *this = *this / v; }
  bool operator<(const bigint &v) const {
    if (sign != v.sign) return sign < v.sign;
    if (a.size() != v.a.size()) return a.size() * sign < v.a.size() * v.sign;
    for (int i = a.size() - 1; i >= 0; i--)
      if (a[i] != v.a[i]) return a[i] * sign < v.a[i] * sign;
    return false;
  }
  bool operator>(const bigint &v) const { return v < *this; }
  bool operator<=(const bigint &v) const { return !(v < *this); }
  bool operator>=(const bigint &v) const { return !(*this < v); }
  bool operator==(const bigint &v) const {
    return !(*this < v) && !(v < *this);
  }
  bool operator!=(const bigint &v) const { return *this < v || v < *this; }
  void trim() {
    while (!a.empty() && !a.back()) a.pop_back();
    if (a.empty()) sign = 1;
  }
  bool isZero() const { return a.empty() || (a.size() == 1 && !a[0]); }
  bigint operator-() const {
    bigint res = *this;
    res.sign = -sign;
    return res;
  }
  bigint abs() const {
    bigint res = *this;
    res.sign *= res.sign;
    return res;
  }
  long long longValue() const {
    long long res = 0;
    for (int i = a.size() - 1; i >= 0; i--) res = res * base + a[i];
    return res * sign;
  }
  friend bigint gcd(const bigint &a, const bigint &b) {
    return b.isZero() ? a : gcd(b, a % b);
  }
  friend bigint lcm(const bigint &a, const bigint &b) {
    return a / gcd(a, b) * b;
  }
  void read(const string &s) {
    sign = 1;
    a.clear();
    int pos = 0;
    while (pos < (int)s.size() && (s[pos] == '-' || s[pos] == '+')) {
      if (s[pos] == '-') sign = -sign;
      ++pos;
    }
    for (int i = s.size() - 1; i >= pos; i -= base_digits) {
      int x = 0;
      for (int j = max(pos, i - base_digits + 1); j <= i; j++)
        x = x * 10 + s[j] - '0';
      a.push_back(x);
    }
    trim();
  }
  friend istream &operator>>(istream &stream, bigint &v) {
    string s;
    stream >> s;
    v.read(s);
    return stream;
  }
  friend ostream &operator<<(ostream &stream, const bigint &v) {
    if (v.sign == -1) stream << '-';
    stream << (v.a.empty() ? 0 : v.a.back());
    for (int i = (int)v.a.size() - 2; i >= 0; --i)
      stream << setw(base_digits) << setfill('0') << v.a[i];
    return stream;
  }
  static vector<int> convert_base(const vector<int> &a, int old_digits,
                                  int new_digits) {
    vector<long long> p(max(old_digits, new_digits) + 1);
    p[0] = 1;
    for (int i = 1; i < (int)p.size(); i++) p[i] = p[i - 1] * 10;
    vector<int> res;
    long long cur = 0;
    int cur_digits = 0;
    for (int i = 0; i < (int)a.size(); i++) {
      cur += a[i] * p[cur_digits];
      cur_digits += old_digits;
      while (cur_digits >= new_digits) {
        res.push_back((int)(cur % p[new_digits]));
        cur /= p[new_digits];
        cur_digits -= new_digits;
      }
    }
    res.push_back((int)cur);
    while (!res.empty() && !res.back()) res.pop_back();
    return res;
  }
  static vector<long long> karatsubaMultiply(const vector<long long> &a,
                                             const vector<long long> &b) {
    int n = a.size();
    vector<long long> res(n + n);
    if (n <= 32) {
      for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++) res[i + j] += a[i] * b[j];
      return res;
    }
    int k = n >> 1;
    vector<long long> a1(a.begin(), a.begin() + k);
    vector<long long> a2(a.begin() + k, a.end());
    vector<long long> b1(b.begin(), b.begin() + k);
    vector<long long> b2(b.begin() + k, b.end());
    vector<long long> a1b1 = karatsubaMultiply(a1, b1);
    vector<long long> a2b2 = karatsubaMultiply(a2, b2);
    for (int i = 0; i < k; i++) a2[i] += a1[i];
    for (int i = 0; i < k; i++) b2[i] += b1[i];
    vector<long long> r = karatsubaMultiply(a2, b2);
    for (int i = 0; i < (int)a1b1.size(); i++) r[i] -= a1b1[i];
    for (int i = 0; i < (int)a2b2.size(); i++) r[i] -= a2b2[i];
    for (int i = 0; i < (int)r.size(); i++) res[i + k] += r[i];
    for (int i = 0; i < (int)a1b1.size(); i++) res[i] += a1b1[i];
    for (int i = 0; i < (int)a2b2.size(); i++) res[i + n] += a2b2[i];
    return res;
  }
  bigint operator*(const bigint &v) const {
    vector<int> a6 = convert_base(this->a, base_digits, 6);
    vector<int> b6 = convert_base(v.a, base_digits, 6);
    vector<long long> a(a6.begin(), a6.end());
    vector<long long> b(b6.begin(), b6.end());
    while (a.size() < b.size()) a.push_back(0);
    while (b.size() < a.size()) b.push_back(0);
    while (a.size() & (a.size() - 1)) a.push_back(0), b.push_back(0);
    vector<long long> c = karatsubaMultiply(a, b);
    bigint res;
    res.sign = sign * v.sign;
    for (int i = 0, carry = 0; i < (int)c.size(); i++) {
      long long cur = c[i] + carry;
      res.a.push_back((int)(cur % 1000000));
      carry = (int)(cur / 1000000);
    }
    res.a = convert_base(res.a, 6, base_digits);
    res.trim();
    return res;
  }
};
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n;
  cin >> n;
  map<long long int, vector<string>> mp;
  for (long long int i = 0; i < n; i++) {
    string s;
    cin >> s;
    long long int c = 0;
    for (auto x : s) {
      if (x == 'a' || x == 'e' || x == 'i' || x == 'o' || x == 'u') {
        c++;
      }
    }
    mp[c].push_back(s);
  }
  vector<string> v1, v2;
  for (auto it : mp) {
    map<char, vector<string>> mm;
    for (long long int i = 0; i < mp[it.first].size(); i++) {
      string s = mp[it.first][i];
      long long int r = s.size() - 1;
      char x;
      while (r >= 0) {
        x = s[r];
        if (x == 'a' || x == 'e' || x == 'i' || x == 'o' || x == 'u') {
          break;
        }
        r--;
      }
      mm[x].push_back(s);
    }
    for (char x = 'a'; x <= 'z'; x++) {
      for (long long int i = 0; i < mm[x].size(); i++) {
        if (i == mm[x].size() - 1) {
          v1.push_back(mm[x][i]);
        } else {
          v2.push_back(mm[x][i]);
          v2.push_back(mm[x][i + 1]);
          i++;
        }
      }
    }
    if (v1.size() % 2 != 0) {
      v1.pop_back();
    }
  }
  long long int l1 = 0, r1 = 0;
  vector<string> ans;
  if (v1.size() != 0 && v2.size() != 0) {
    for (long long int i = 0; i < min(v1.size(), v2.size()); i += 2) {
      ans.push_back(v1[i]);
      ans.push_back(v2[i]);
      ans.push_back(v1[i + 1]);
      ans.push_back(v2[i + 1]);
      l1 += 2;
      r1 += 2;
    }
  }
  l1 = v2.size() - (long long int)1;
  while ((l1 - r1) >= 3) {
    ans.push_back(v2[l1]);
    ans.push_back(v2[r1]);
    ans.push_back(v2[l1 - 1]);
    ans.push_back(v2[r1 + 1]);
    l1 -= 2;
    r1 += 2;
  }
  cout << ans.size() / 4 << endl;
  for (long long int i = 0; i < ans.size(); i += 4) {
    cout << ans[i] << " " << ans[i + 1] << endl;
    cout << ans[i + 2] << " " << ans[i + 3] << endl;
  }
  return 0;
}