## https://yukicoder.me/problems/no/669


def solve(H_, W_, K):
    s_map = {}
    s_array = []
    r = (0, 0)
    ind = 0
    while r not in s_map:
        s_map[r] = ind
        s_array.append(r)
        r = ((r[0] + 1) % H_, (r[1] + 1) % W_)
        ind += 1

    ans_map = {}
    if ind >= K:
        for i in range(K):
            s = s_array[i]
            ans_map[s] = 1
        return ans_map
    else:
        s_ind = s_map[r]
        cycle = ind - s_ind

        # 初手の動き    
        for i in range(s_ind):
            s = s_array[i]
            ans_map[s] = 1

        K -= s_ind
        # 周期
        k = K // cycle
        for i in range(s_ind, ind):
            s = s_array[i]
            ans_map[s] = k
        
        # 最後っ屁
        k0 = K - cycle * k
        for i in range(k0):
            s = s_array[i + s_ind]
            if s not in ans_map:
                ans_map[s] = 0
            ans_map[s] += 1
        
        return ans_map



def main():
    H, W = map(int, input().split())
    K = int(input())

    H_ = 2 * H
    W_ = 2 * W

    ans_map = solve(H_, W_, K)

    cell = [[0] * W for _ in range(H)]
    for key, value in ans_map.items():
        h0, w0 = key
        h = h0 if h0 < H else H_ - h0 - 1
        w = w0 if w0 < W else W_ - w0 - 1
        cell[h][w] += value
    for h in range(H):
        for w in range(W):
            v = cell[h][w]
            if v % 2 == 0:
                cell[h][w] = "."
            else:
                cell[h][w] = "#"
        
    for h in range(H):
        row = "".join(cell[h])
        print(row)







if __name__ == "__main__":
    main()