def solve(i):
    ls = i.splitlines()
    lc = len(ls)

    def axes_pos(x, y):
        return y, x + y, lc - 1 - y + x

    I = 2 ** 64
    bmin = (I, I, I)
    bmax = (0, 0, 0)

    for y, line in enumerate(ls):
        for x, char in enumerate(line):
            if char != '#': continue
            p = axes_pos(x, y)
            bmax = tuple(map(max, bmax, p))
            bmin = tuple(map(min, bmin, p))

    result = ''
    for y, line in enumerate(ls):
        # if y > 0: result += '\n'
        for x, char in enumerate(line):
            if char != '.':
                result += char
            else:
                p = axes_pos(x, y)
                f = all(bmin[j] <= p[j] <= bmax[j] for j in range(0, 3))
                result += '#' if f else char
        result += '\n'

    return result


def run_test(a, b):
    result = solve(a)
    if result != b:
        raise AssertionError('\n' + result + '\n\nshould be equal to\n\n' + b)


def run_tests():
    run_test(
        "#\n",

        "#\n")

    run_test(
        " . . \n"
        "# . #\n"
        " . . \n",

        " . . \n"
        "# # #\n"
        " . . \n")

    run_test(
        " . # \n"
        ". . .\n"
        " # . \n",

        " . # \n"
        ". # .\n"
        " # . \n")

    run_test(
        " # . \n"
        ". . .\n"
        " . # \n",

        " # . \n"
        ". # .\n"
        " . # \n")

    run_test(
        " # . \n"
        "# . .\n"
        " . # \n",

        " # . \n"
        "# # .\n"
        " # # \n")

    run_test(
        " . # \n"
        "# . .\n"
        " . # \n",

        " # # \n"
        "# # #\n"
        " # # \n")

    run_test(
        ". . . . . . . . \n"
        " . . # . # . . .\n"
        ". . . . . . . . \n"
        " . . . # . . . .\n",

        ". . . . . . . . \n"
        " . . # # # . . .\n"
        ". . . # # . . . \n"
        " . . . # . . . .\n")

    run_test(
        ". . . . . . . . \n"
        " . . # . . . # .\n"
        ". . . . . . . . \n"
        " . . . # . . . .\n",

        ". . . . . . . . \n"
        " . . # # # # # .\n"
        ". . . # # # # . \n"
        " . . . # # # . .\n")

    run_test(
        ". . . . . . . . \n"
        " . # . . . . . .\n"
        ". . . . . # . . \n"
        " . . . . . . . .\n",

        ". . . . . . . . \n"
        " . # # # # . . .\n"
        ". . # # # # . . \n"
        " . . . . . . . .\n")

    run_test(
        ". . . . . . . . \n"
        " . # . . . . . .\n"
        ". . . . . # . . \n"
        " . . # . . . . .\n",

        ". . . . . . . . \n"
        " . # # # # . . .\n"
        ". . # # # # . . \n"
        " . . # # # . . .\n")

    run_test(
        ". . . . # . . . \n"
        " . # . . . # . .\n"
        ". . . # . . . . \n"
        " . . . . . # . .\n",

        ". . # # # # . . \n"
        " . # # # # # . .\n"
        ". . # # # # # . \n"
        " . . # # # # . .\n")


if __name__ == '__main__':
    run_tests()