import sys
input = sys.stdin.readline
T = int(input())
N = [int(input()) for _ in range(T)]
ABC = "ABC"
for n in N:
    ans = []
    for _ in range(n):
        if len(ans)>0:
            c = ans.pop()
            ans.append(ABC[0])
            ans.append(c)
            ans.extend(list(ABC[1:]))
        else:
            ans.extend(list(ABC))
    print("".join(ans))