python

真不知道错在哪里 自测样例能过，但提交过不了

print('Impossible')的部分应该没问题

但是输出座位图有问题

n, m = map(int, input().split())
t, p = [], []
k, x, mx= 0, 0, 0
for _ in range(n):
    h = input()
    k += h.count('.')
    x += h.count('X')
    t.append(h)
if (x+m)%2 == 0 and m <= k:
    d = 0
    for ti in t:
        l = ti[:3]
        r = ti[3:][::-1]
        pi = ''
        for li, ri in zip(l, r):
            if li != ri:
                pi += 'X'
                d += 1
            else:
                pi += li
        mx += 2*pi.count('X')
        p.append(pi)
    if d <= m:
        b = (m+x-mx)//2
        for j in range(len(p)):
            ck = p[j].count('.')
            if ck > b:
                p[j] = p[j].replace('.', 'X', b)
                break
            else:
                p[j] = 'XXX'
                b -= ck
        for pii in p:
            print(f'{pii}{pii[::-1]}')
    else:
        print('Impossible')
else:
    print('Impossible')