#D5499. B Palindrome
B Palindrome
B Palindrome
You are given a string s consisting of the characters '0', '1', and '?'. You need to replace all the characters with '?' in the string s by '0' or '1' so that the string becomes a palindrome and has exactly a characters '0' and exactly b characters '1'. Note that each of the characters '?' is replaced independently from the others.
A string t of length n is called a palindrome if the equality t[i] = t[n-i+1] is true for all i (1 ≤ i ≤ n).
For example, if s="01?????0", a=4 and b=4, then you can replace the characters '?' in the following ways:
- "01011010";
- "01100110".
For the given string s and the numbers a and b, replace all the characters with '?' in the string s by '0' or '1' so that the string becomes a palindrome and has exactly a characters '0' and exactly b characters '1'.
Input
The first line contains a single integer t (1 ≤ t ≤ 10^4). Then t test cases follow.
The first line of each test case contains two integers a and b (0 ≤ a, b ≤ 2 ⋅ 10^5, a + b ≥ 1).
The second line of each test case contains the string s of length a+b, consisting of the characters '0', '1', and '?'.
It is guaranteed that the sum of the string lengths of s over all test cases does not exceed 2 ⋅ 10^5.
Output
For each test case, output:
- "-1", if you can't replace all the characters '?' in the string s by '0' or '1' so that the string becomes a palindrome and that it contains exactly a characters '0' and exactly b characters '1';
- the string that is obtained as a result of the replacement, otherwise.
If there are several suitable ways to replace characters, you can output any.
Example
Input
9 4 4 01?????0 3 3 ?????? 1 0 ? 2 2 0101 2 2 01?0 0 1 0 0 3 1?1 2 2 ?00? 4 3 ??010?0
Output
01011010 -1 0 -1 0110 -1 111 1001 0101010
inputFormat
Input
The first line contains a single integer t (1 ≤ t ≤ 10^4). Then t test cases follow.
The first line of each test case contains two integers a and b (0 ≤ a, b ≤ 2 ⋅ 10^5, a + b ≥ 1).
The second line of each test case contains the string s of length a+b, consisting of the characters '0', '1', and '?'.
It is guaranteed that the sum of the string lengths of s over all test cases does not exceed 2 ⋅ 10^5.
outputFormat
Output
For each test case, output:
- "-1", if you can't replace all the characters '?' in the string s by '0' or '1' so that the string becomes a palindrome and that it contains exactly a characters '0' and exactly b characters '1';
- the string that is obtained as a result of the replacement, otherwise.
If there are several suitable ways to replace characters, you can output any.
Example
Input
9 4 4 01?????0 3 3 ?????? 1 0 ? 2 2 0101 2 2 01?0 0 1 0 0 3 1?1 2 2 ?00? 4 3 ??010?0
Output
01011010 -1 0 -1 0110 -1 111 1001 0101010
样例
9
4 4
01?????0
3 3
??????
1 0
?
2 2
0101
2 2
01?0
0 1
0
0 3
1?1
2 2
?00?
4 3
??010?0
01011010
-1
0
-1
0110
-1
111
1001
0101010
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