import math

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

def lcm(a, b):
    return a * b // math.gcd(a, b)

c = lcm(2 * h, 2 * w)

current_row = 1
current_col = 1
v_dir = 1  # 1 for down, -1 for up
h_dir = 1  # 1 for right, -1 for left

flips_cycle = []

for _ in range(c):
    flips_cycle.append((current_row, current_col))
    # Process vertical movement
    next_row = current_row + v_dir
    if 1 <= next_row <= h:
        current_row = next_row
    else:
        v_dir *= -1
    # Process horizontal movement
    next_col = current_col + h_dir
    if 1 <= next_col <= w:
        current_col = next_col
    else:
        h_dir *= -1

q, r = divmod(k, c)

# Compute flips in cycle
flips_in_cycle = {}
for coord in flips_cycle:
    if coord in flips_in_cycle:
        flips_in_cycle[coord] += 1
    else:
        flips_in_cycle[coord] = 1

# Compute flips in residual
flips_in_residual = {}
for coord in flips_cycle[:r]:
    if coord in flips_in_residual:
        flips_in_residual[coord] += 1
    else:
        flips_in_residual[coord] = 1

# Prepare the grid
grid = [['.' for _ in range(w)] for _ in range(h)]
for i in range(h):
    for j in range(w):
        coord = (i+1, j+1)
        cycle_count = flips_in_cycle.get(coord, 0)
        residual_count = flips_in_residual.get(coord, 0)
        total_parity = ((cycle_count % 2) * (q % 2) + residual_count % 2) % 2
        if total_parity:
            grid[i][j] = '#'

for row in grid:
    print(''.join(row))