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: '''
    0123456
    abababa
  
    every even substring occurs uneven number of times in an even string
    every uneven substring occurs even number of times in an even string
  
    every even substring occurs even number of times in an uneven string
    every uneven substring occurs uneven number of times in an uneven string
  
    let's say you've got an even string of 'aaa...aa', split it into two
      the first half is uneven 
        which means that that it has even number of pairity
        and un even number of odd substrings
  
        to correct that
          swap out one character in the second half (assume first one)
            then you'll have
              even substrings: parity + odd = odd  
              uneven substrings: odd + parity = odd
  
  
    let's say you've got an uneven string of 'aaa..aa', split it into two
      both half's are going to be even but you can make one half uneven by swapping out a leading 'a'
  
      a
      ab
      abc
  '''
  
  t = int(input())
  for _ in range(t):
    n = int(input())
    if n == 1:
      print('a')
    else:
      lhs = 'a' * (n // 2)
  
      pivot = 'b' * (n % 2)
      lead = 'c'
  
      rhs = 'a' * (n // 2 - 1)
  
      print(lhs + pivot + lead + rhs)
  