def FJ(n):
    if n == 1:
        return "A"
    else:
        m = ord('A') + n - 1
        m = chr(m)
        return FJ(n - 1) + m + FJ(n - 1)
n = int(input())
print(FJ(n))


/**************************************************************
	Problem: 1474
	User: admin
	Language: Python
	Result: Accepted
	Time:250 ms
	Memory:34244 kb
****************************************************************/