N=int(input())
import itertools
alpha="abcdefghijklmnopqrstuvwxyz"
i=1
word_list=list(alpha)
random_word=list(itertools.combinations_with_replacement(word_list,17))
for j in random_word:
    aida="".join(j)
    output="a"+aida+"a"

    if i==N:
        output=output+"n"
        print(output)
        break
    print(output)
    i+=1