#include <bits/stdc++.h>
using namespace std;
double tick() {
  static clock_t oldtick;
  clock_t newtick = clock();
  double diff = 1.0 * (newtick - oldtick) / CLOCKS_PER_SEC;
  oldtick = newtick;
  return diff;
}
long long gcd(long long a, long long b) {
  if ((a == 0) || (b == 0)) {
    return a + b;
  }
  return gcd(b, a % b);
}
long long powMod(long long a, long long b) {
  long long res = 1;
  while (b) {
    if (b & 1) res = (res * a) % 1000000007;
    a = (a * a) % 1000000007;
    b >>= 1;
  }
  return (res % 1000000007);
}
long long pow2(long long a, long long b) {
  long long res = 1;
  while (b) {
    if (b & 1) res = (res * a);
    a = (a * a);
    b >>= 1;
  }
  return res;
}
bool isPrime(long long a) {
  for (long long i = 3; (i * i) <= a; i += 2) {
    if ((a % i) == 0) return false;
  }
  if ((a != 2) && ((a % 2) == 0)) {
    return false;
  }
  if (a == 1) {
    return false;
  }
  return true;
}
string conLlToStr(long long a) {
  stringstream mystr;
  mystr << a;
  return mystr.str();
}
long long conStrToLl(string st) {
  long long numb = 0;
  long long len = st.size(), i, j = 0;
  for (long long i = len - 1; i >= 0; i--) {
    numb += (pow2(10, j) * (st[i] - '0'));
    j++;
  }
  return numb;
}
long long basenoToDecimal(string st, long long basee) {
  long long i = 0, j, anss = 0;
  for (long long j = (int)st.length() - 1; j >= 0; j--) {
    anss += (st[j] - '0') * pow2(basee, i);
    i++;
  }
  return anss;
}
string decimalToString(long long num, long long basee) {
  long long i = 0, j, opop;
  string anss = "";
  vector<string> stri;
  stri.push_back("0");
  stri.push_back("1");
  stri.push_back("2");
  stri.push_back("3");
  stri.push_back("4");
  stri.push_back("5");
  stri.push_back("6");
  stri.push_back("7");
  stri.push_back("8");
  stri.push_back("9");
  stri.push_back("A");
  stri.push_back("B");
  stri.push_back("C");
  stri.push_back("D");
  stri.push_back("E");
  stri.push_back("F");
  if (num == 0) {
    return "0";
  }
  while (num) {
    opop = (num % basee);
    anss += stri[opop];
    num /= basee;
  }
  reverse(anss.begin(), anss.end());
  return anss;
}
long long my_sqrt(long long x) {
  long long y = (long long)(sqrtl((long double)x) + 0.5);
  while (y * y < x) {
    y++;
  }
  while (y * y > x) {
    y--;
  }
  if (y * y == x) {
    return y;
  }
  return -1;
}
long long my_crt(long long x) {
  long long y = (long long)(powl((long double)x, 1.0 / 3.0) + 0.5);
  while (y * y * y < x) {
    y++;
  }
  while (y * y * y > x) {
    y--;
  }
  if (y * y * y == x) {
    return y;
  }
  return -1;
}
const int dx[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int dy[] = {1, 1, 0, -1, -1, -1, 0, 1};
string S[100010];
vector<string> stringContained[100010][30];
vector<pair<string, string> > firstString, secondString;
vector<pair<pair<string, string>, pair<string, string> > > ans;
set<int> numVowel;
vector<string> temp;
bool isVowel(char ch) {
  if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') {
    return 1;
  }
  return 0;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int N;
  cin >> N;
  for (long long i = 1; i <= N; i++) {
    cin >> S[i];
    int vowel = 0;
    char lastVowel;
    for (long long j = 0; j <= (int)S[i].length() - 1; j++) {
      if (isVowel(S[i][j])) {
        vowel++;
        lastVowel = S[i][j];
      }
    }
    if (vowel) {
      numVowel.insert(vowel);
      stringContained[vowel][lastVowel - 'a'].push_back(S[i]);
    }
  }
  for (auto it = numVowel.begin(); it != numVowel.end(); ++it) {
    int i = (*it);
    for (long long j = 0; j <= 25; j++) {
      for (int k = 0; k < (int)stringContained[i][j].size(); k += 2) {
        if ((k + 1) < (int)stringContained[i][j].size()) {
          secondString.push_back(make_pair(stringContained[i][j][k],
                                           stringContained[i][j][k + 1]));
        }
      }
      if (stringContained[i][j].size() % 2) {
        temp.push_back(stringContained[i][j][stringContained[i][j].size() - 1]);
      }
    }
    for (int k = 0; k < (int)temp.size(); k += 2) {
      if ((k + 1) < (int)temp.size()) {
        firstString.push_back(make_pair(temp[k], temp[k + 1]));
      }
    }
    temp.clear();
  }
  int ind1 = 0, ind2 = 0;
  while (ind1 < firstString.size() && ind2 < secondString.size()) {
    ans.push_back(make_pair(
        make_pair(firstString[ind1].first, secondString[ind2].first),
        make_pair(firstString[ind1].second, secondString[ind2].second)));
    ind1 += 1;
    ind2 += 1;
  }
  for (int k = ind2; k < (int)secondString.size(); k += 2) {
    if ((k + 1) < (int)secondString.size()) {
      ans.push_back(make_pair(
          make_pair(secondString[k].first, secondString[k + 1].first),
          make_pair(secondString[k].second, secondString[k + 1].second)));
    }
  }
  cout << ans.size() << "\n";
  for (long long i = 0; i <= (int)ans.size() - 1; i++) {
    cout << ans[i].first.first << " " << ans[i].first.second << "\n";
    cout << ans[i].second.first << " " << ans[i].second.second << "\n";
  }
  return 0;
}
