def terminal(x):
    return (chr(x%12+97),chr((x+1)%12+97))


def middle(x):
    chr_list = [0,0,0,0]
    for i in range(4):
        chr_list[i] = x % 26
        x = x - x % 26
        x = x // 26
    return "".join([ chr(i + 97) for i in chr_list ] ) 
         
n = int(input())

for i in range(n-1):
    s = terminal(i)[0]+middle(i)+terminal(i)[1]
    print(s)
    
if n == 1:
    print("n")
else:
    print(s+"n")