from collections import *
from itertools import *
from functools import *
from heapq import *
import sys,math
input = sys.stdin.readline

def answer():
    
    N = int(input())
    if N%2==0:
        n = N//2
        print("ABACBC"*n)
        return
    else:
        n = N//2
        print('ABACBACBC'+"ABACBC"*(n-1))
        return

for _ in range(int(input())):
    answer()