description: You are given an integer n. Find any string s of length n consisting only of English lowercase letters such that each non-empty substring of s occurs in s an odd number of times. If there are multiple such strings, output any. It can be shown that such string always exists under the given constraints.
  
  A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 500) — the number of test cases.
  
  The first line of each test case contains a single integer n (1 ≤ n ≤ 10^5).
  
  It is guaranteed that the sum of n over all test cases doesn't exceed 3 ⋅ 10^5.
  
  Output
  
  For each test case, print a single line containing the string s. If there are multiple such strings, output any. It can be shown that such string always exists under the given constraints.
  
  Example
  
  Input
  
  
  4
  3
  5
  9
  19
  
  
  Output
  
  
  abc
  diane
  bbcaabbba
  youarethecutestuwuu
  
  Note
  
  In the first test case, each substring of "abc" occurs exactly once.
  
  In the third test case, each substring of "bbcaabbba" occurs an odd number of times. In particular, "b" occurs 5 times, "a" and "bb" occur 3 times each, and each of the remaining substrings occurs exactly once.
solution: import sys
  import math
  from math import *
  import builtins
  import collections
  import bisect
  import os
  from io import BytesIO, IOBase
  
  
  def print(x, end='\n'):
      sys.stdout.write(str(x) + end)
  
  
  # IO helpers
  def get_int():
      return int(input())
  
  
  def get_list_ints():
      return list(map(int, input().split()))
  
  
  def get_char_list():
      s = input()
      return list(s[:len(s) - 1])
  
  
  def get_tuple_ints():
      return tuple(map(int, input().split()))
  
  
  def print_iterable(p):
      print(" ".join(map(str, p)))
  
  def CountFrequency(arr):
      return collections.Counter(arr) 
   
  def reverse(s):
      l=len(s)
      for i in range(l//2):
          s[i],s[l-i-1]=s[l-i-1],s[i]
      return s
  
  
  def binary_search(arr, x):
      low = 0
      high = len(arr) - 1
      mid = 0
      while low <= high:
          mid = (high + low) // 2
          if arr[mid] < x:
              low = mid + 1
          elif arr[mid] > x:
              high = mid - 1
          else:
              return mid
      return high
  
  #STD lower bound equivalent in python
  def lower_bound(arr,x):
      return bisect.bisect_left(arr, x, lo=0, hi=len(arr))
   
   #STD upper bound equivalent in python
  def upper_bound(arr,x):
      return bisect.bisect_right(arr, x, lo=0, hi=len(arr))
  
  
  def pow(a,n):
      if n==0:
          return 1
      elif n%2==0:
          return ((pow(a,n//2)%const)*(pow(a,n//2)%const))%const
      else:
          return ((pow(a,n//2)%const)*(pow(a,n//2)%const)*(a%const))%const
  
  def main(): 
      n=get_int()
      for i in range(n):
          l=get_int()
          if l%2==0:
              stri="b"*(l//2-1)+"a"+"b"*(l//2)
              print(stri)
          else:
              if l==1:
                  print("a")
              else:
                  stri=((l-1)//2)*"a"+"bc"+((l-1)//2-1)*"a"
                  print(stri)
      pass
  
  
  ##Fast Input Output
  
  BUFSIZE = 8192
  
  
  class FastIO(IOBase):
      newlines = 0
  
      def __init__(self, file):
          self._fd = file.fileno()
          self.buffer = BytesIO()
          self.writable = "x" in file.mode or "r" not in file.mode
          self.write = self.buffer.write if self.writable else None
  
      def read(self):
          while True:
              b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
              if not b:
                  break
              ptr = self.buffer.tell()
              self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
          self.newlines = 0
          return self.buffer.read()
  
      def readline(self):
          while self.newlines == 0:
              b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
              self.newlines = b.count(b"\n") + (not b)
              ptr = self.buffer.tell()
              self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
          self.newlines -= 1
          return self.buffer.readline()
  
      def flush(self):
          if self.writable:
              os.write(self._fd, self.buffer.getvalue())
              self.buffer.truncate(0), self.buffer.seek(0)
  
  
  class IOWrapper(IOBase):
      def __init__(self, file):
          self.buffer = FastIO(file)
          self.flush = self.buffer.flush
          self.writable = self.buffer.writable
          self.write = lambda s: self.buffer.write(s.encode("ascii"))
          self.read = lambda: self.buffer.read().decode("ascii")
          self.readline = lambda: self.buffer.readline().decode("ascii")
  
  
  sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
  input = lambda: sys.stdin.readline().rstrip("\r\n")
  
  # endregion
  
  if __name__ == "__main__":
      main()