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

x,y = 0,0
dx,dy = 1,1

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

for _ in range(k):
    if s[x][y] == ".":
        s[x][y] = "#"
    else:
        s[x][y] = "."

    if x + dx < 0 or x + dx >= h:
        dx *= -1
    else:
        x += dx
    if y + dy < 0 or y + dy >= w:
        dy *= -1
    else:
        y += dy

for i in s:
    print("".join(i))