a = int(input())
arr = []
s = "abcdefghijklmnopqrstuvwxyz"
if a == 1:
    print("a")
else:
    first = s[0]
    arr.append(first*(a-1))
    for i in range(a-1):
        arr.append(first+s[i+1])
for i in range(len(arr)):
    print(arr[i])