#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using db = double;
using ld = long double;
template <typename T>
using V = vector<T>;
template <typename T>
using VV = vector<vector<T>>;
template <typename T>
using PQ = priority_queue<T>;
template <typename T>
using PQR = priority_queue<T, vector<T>, greater<T>>;
constexpr ll mod = 1000000007;
constexpr ll INF = 1000000099;
constexpr ll LINF = (ll)(1e18 + 99);
const ld PI = acos((ld)-1);
constexpr ll dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
template <typename T, typename U>
inline bool chmin(T &t, const U &u) {
  if (t > u) {
    t = u;
    return 1;
  }
  return 0;
}
template <typename T, typename U>
inline bool chmax(T &t, const U &u) {
  if (t < u) {
    t = u;
    return 1;
  }
  return 0;
}
template <typename T>
inline T gcd(T a, T b) {
  return b ? gcd(b, a % b) : a;
}
inline void Yes() { cout << "Yes" << '\n'; }
inline void No() { cout << "No" << '\n'; }
inline void YES() { cout << "YES" << '\n'; }
inline void NO() { cout << "NO" << '\n'; }
template <typename T, typename Y>
inline T mpow(T a, Y n) {
  T res = 1;
  for (; n; n >>= 1) {
    if (n & 1) res = res * a;
    a = a * a;
  }
  return res;
}
template <typename T>
vector<T> finddivisor(T x) {
  vector<T> divisor;
  for (T i = 1; (i * i) <= x; i++) {
    if (x % i == 0) {
      divisor.push_back(i);
      if (i * i != x) {
        divisor.push_back(x / i);
      }
    }
  }
  sort(divisor.begin(), divisor.end());
  return divisor;
}
template <typename T>
V<T> prefix_sum(const V<T> &v) {
  int n = v.size();
  V<T> ret(n + 1);
  for (ll i = 0; i < (ll)(n); ++i) ret[i + 1] = ret[i] + v[i];
  return ret;
}
template <typename T>
T rand(T l, T r) {
  static random_device rd;
  static mt19937 g(rd());
  return uniform_int_distribution<T>(l, r)(g);
}
template <typename T>
istream &operator>>(istream &is, vector<T> &vec) {
  for (auto &&x : vec) is >> x;
  return is;
}
template <typename T, typename Y>
ostream &operator<<(ostream &os, const pair<T, Y> &p) {
  return os << "{" << p.first << "," << p.second << "}";
}
template <typename T>
ostream &operator<<(ostream &os, const V<T> &v) {
  os << "{";
  for (auto e : v) os << e << ",";
  return os << "}";
}
template <typename... Args>
void debug(Args &...args) {
  for (auto const &x : {args...}) {
    cerr << x << ' ';
  }
  cerr << '\n';
}
signed main() {
  cin.tie(0);
  cerr.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(20);
  int qq;
  cin >> qq;
  while (qq--) {
    ll n;
    cin >> n;
    string ans(n, 'a');
    if (n >= 2) ans[n / 2 - 1] = 'b';
    if (n % 2) {
      ans.back() = 'c';
    }
    cout << ans << '\n';
  }
}
