n=int(input())
#ans=[]
num=(2**(n-1))
for i in range(num):
    b=(bin(i)[2:].zfill(n))
    tmp=""
    for each in b:
        if each=="0":
            tmp+="a"
        else:
            tmp+="b"
    #ans.append(tmp)
    print(tmp)
#print(ans)