for _ in range(int(input())):
  n=int(input())
  s=list("_"*5*n)
  for i in range(n):
    s[i*3+0]="A"
    s[i*3+2]="B"
    s[i*3+4]="C"
  t=""
  for c in s:
    if c!="_":
      t+=c
  print(t)