7 2
-10 0 ? 1 ? 2 10
 1 1
0
 5 1
-3 -2 -1 0 1
 7 1
-4 ? ? ? ? ? 2
 17 1
? -13 ? ? ? -3 ? ? ? ? ? 10 ? ? ? ? 100
 3 1
-5 ? 0
 7 2
-10 0 ? 1 6 2 ?
 3 1
-3 ? -2
 6 1
-1 ? 1 2 3 4
 1 1
?
 9 2
-10 0 ? 1 ? 2 ? 3 ?
 10 2
3 ? 5 ? 7 ? 9 ? 11 ?
 9 2
? ? -10 ? ? ? 10 ? ?
 9 3
? ? ? ? ? ? ? ? ?
 7 2
? ? 10 ? ? ? ?
 5 1
1000000000 ? ? ? ?
 7 3
1 ? -1000000000 ? 100 ? 2
 7 2
? ? -10 ? ? ? ?
 39 3
-5 1 -13 ? 2 -12 ? 3 -11 -2 4 -10 ? 5 -9 0 6 -8 ? 7 -7 ? 8 -6 5 9 -5 ? 10 -4 ? 11 -3 ? 12 -2 10 13 -1
 7 2
? ? 10 ? -10 ? ?
 7 1
-2 ? ? ? ? ? 4
 7 2
-10 0 0 1 ? 2 ?
 9 2
-10 0 ? 1 -6 2 ? 3 ?
 7 3
1 ? -1000000000 ? 100 ? 3
 9 2
-10 0 ? 1 ? 2 ? 3 0
 9 2
10 0 ? 1 ? 2 ? 3 ?
 3 1
-1 ? 1
 10 1
-2 ? ? ? ? ? ? 5 ? 10
 5 2
? ? -1000000000 ? ?
 2 1
-1000000000 1000000000
 7 2
-10 0 ? 1 -6 2 ?
 5 4
-1 ? ? ? 2
 7 2
10 0 ? 1 ? 2 ?
 7 2
-10 0 ? 1 ? 2 0
 7 2
-10 0 ? 1 ? 2 ?
 7 2
? ? -10 ? 10 ? ?
 6 1
-3 ? ? ? ? 3
 9 2
-10 0 ? 1 ? 2 ? 3 10
 3 1
4 ? 5
 9 3
-5 0 -1 ? ? ? 0 5 1
 7 1
-3 ? ? ? ? ? 3

-10 0 -1 1 0 2 10
 0
 -3 -2 -1 0 1
 -4 -3 -2 -1 0 1 2
 -14 -13 -6 -5 -4 -3 -2 -1 0 1 2 10 11 12 13 14 100
 -5 -1 0
 -10 0 0 1 6 2 7
 Incorrect sequence
 -1 0 1 2 3 4
 0
 -10 0 -2 1 -1 2 0 3 1
 3 -2 5 -1 7 0 9 1 11 2
 -11 -2 -10 -1 0 0 10 1 11
 -1 -1 -1 0 0 0 1 1 1
 0 -1 10 0 11 1 12
 1000000000 1000000001 1000000002 1000000003 1000000004
 Incorrect sequence
 -11 -1 -10 0 -1 1 0
 -5 1 -13 -4 2 -12 -3 3 -11 -2 4 -10 -1 5 -9 0 6 -8 1 7 -7 2 8 -6 5 9 -5 6 10 -4 7 11 -3 8 12 -2 10 13 -1
 Incorrect sequence
 -2 -1 0 1 2 3 4
 -10 0 0 1 1 2 2
 -10 0 -7 1 -6 2 -1 3 0
 1 0 -1000000000 2 100 0 3
 -10 0 -3 1 -2 2 -1 3 0
 10 0 11 1 12 2 13 3 14
 -1 0 1
 -2 -1 0 1 2 3 4 5 6 10
 -1000000001 -1 -1000000000 0 0
 -1000000000 1000000000
 -10 0 -7 1 -6 2 0
 -1 0 0 0 2
 10 0 11 1 12 2 13
 -10 0 -2 1 -1 2 0
 -10 0 -1 1 0 2 1
 -11 -1 -10 0 10 1 11
 -3 -2 -1 0 1 3
 -10 0 -1 1 0 2 1 3 10
 Incorrect sequence
 -5 0 -1 -1 1 0 0 5 1
 -3 -2 -1 0 1 2 3 

#!/usr/bin/env python3

import sys

N, K = input().split(' ')
N = int(N)
K = int(K)

a = input().split(' ')
a = list(map(lambda x: x if x == '?' else int(x), a))

N = len(a)

known_idxs = [i for i, e in enumerate(a) if e != '?']

def fail():
    print('Incorrect sequence')
    sys.exit(0)

def do_fix(aa, b, c, d, e, f = 1):
    assert(len(range(aa, b, c)) == len(range(d, e, f)))
    a[aa:b:c] = range(d, e, f)

def fix(start, end):

    # print("fixing", a[start:end+1:K])

    l = len(range(start, end, K))

    if (a[start] == '?' and a[end] != '?'):
        if a[end] >= 0:
            s = min(0, a[end] - l)
            do_fix(start, end, K, s, s + l)
            # a[start:end:K] = range(s, s + l)
        elif a[end] < 0:
            do_fix(start, end, K, l + a[end], a[end], -1)
            # a[start:end:K] = range(l + a[end], a[end], -1)
    elif (a[start] != '?' and a[end] == '?'):
        if a[start] >= 0:
            do_fix(start, end+1, K, a[start], a[start] + l + 1)
            # a[start:end+1:K] = range(a[start], a[start] + l + 1)
        elif a[start] < 0:
            e = max(0, a[start] + l)
            do_fix(start+K, end+1, K, e-l+1, e+1)
            # a[start+K:end+1:K] = range(e-l+1, e+1)
    elif (a[start] == '?' and a[end] == '?'):
        s = -((l + 1) // 2)
        do_fix(start, end+1, K, s, s+l+1)
        # a[start:end+1:K] = range(s, s + l + 1)
    elif (a[start] != '?' and a[end] != '?'):
        if a[end] - a[start] < l:
            fail()
        elif 0 <= a[start]:
            do_fix(start, end, K, a[start], a[start] + l)
            # a[start:end:K] = range(a[start], a[start] + l)
        elif a[end] <= 0:
            do_fix(start+1, end+1, K, a[end]-l+1, a[end]+1)
            # a[start+1:end+1:K] = range(a[end] - l + 1, a[end] + 1)
        else:
            left_0 = l - a[end] - 1
            right_0 = -1 - a[start]
            opt_0 = (l - 1) // 2
            opt_0 = min(opt_0, right_0)
            opt_0 = max(opt_0, left_0)

            s = -opt_0
            do_fix(start+K, end, K, s, s+l-1)
            # a[start+K:end:K] = range(s, s + l - 1)
    else:
        print('Impossible')

for s in range(0, K):
    sub_idxs = list(range(s, N, K))

    sub_ki = [i for i in sub_idxs if i in known_idxs]
    if sub_idxs[0] not in sub_ki:
        sub_ki = [sub_idxs[0]] + sub_ki
    if sub_idxs[-1] not in sub_ki:
        sub_ki = sub_ki + [sub_idxs[-1]]

    for i in range(0, len(sub_ki) - 1):
        fix(sub_ki[i], sub_ki[i + 1])

print(' '.join(map(str, a)))