alf = list("abcdefghijklmnopqrstuvwxyz")

n = int(input())

ans = ["" for i in range(n)]

for i in range(n):
    for j in range(n):
        if j >= i:
            ans[j] += alf[i]
        else:
            ans[j] += alf[j]

print(*ans, sep="\n")
