h, w = map(int, input().split())
k = int(input())

s = [[0 for j in range(w)] for i in range(h)]

from math import gcd
d = gcd(h, w) * 2

l = h * w * 4 // d

for t in range(l):
    i = t % (2 * h)
    j = t % (2 * w)
    s[min(i, 2 * h-1-i)][min(j, 2 * w-1-j)] += max((k-t+l-1)//l, 0)

for i in range(h):
    print("".join([[".", "#"][j%2] for j in s[i]]))