import itertools
def f():
    n=int(input())
    l=[]
    a=itertools.permutations('abcdefghijklmnopqrstuvwxyz',4)
    for i in a:
        l+=["".join(i)]
    l=["a"+l[i]+"a"for i in range(n-1)]
    for i in l:
        print(i)
    return"aaaaan"

print(f())