from math import gcd

H, W = map(int, input().split())
K = int(input())
lcm = H * W // gcd(H, W)
K %= 2 * lcm
x, y = 0, 0
G = [[0] * W for i in range(H)]

def plot(G, x, y):
    x %= 2 * H
    y %= 2 * W
    if x >= H:
        x = 2 * H - 1 - x
    if y >= W:
        y = 2 * W - 1 - y
    G[x][y] = 1 - G[x][y]

for _ in range(K):
    plot(G, x, y)
    x, y = x + 1, y + 1
    
def f(c):
    return "#" if c else "."

for i in range(H):
    ans = list(map(f, G[i]))
    print(*ans, sep="")