Broken Life ~ Multiplex Coder

You are given two strings

S

and

A

of lengths

N

and

M

respectively.

String $S$

contains characters from the set

{?, a, b, c, d, e}

String

A

contains characters from the set

{a, b, c, d, e}

Let $S^{'}$

denote the string formed by replacing all the

?

S

using the characters from the set

{a, b, c, d, e}

.
Construct

S^{'}

such that

A

is not a subsequence of

S^{'}

If multiple such $S^{'}$

exist, output any. If no such

S^{'}

exists, print

- 1

Input Format

The first line will contain $T$

- the number of test cases. Then the test cases follow.

The first line of each test case contains two integers

N

and

M

- the lengths of strings

S

and

A

respectively.

The second line of each test case contains string

S

The third line of each test case contains string

A

Output Format

For each test case, output any valid string $S^{'}$

. If no such string exists, print

- 1

Constraints

$1 \leq T \leq 1000$

1 \leq N, M \leq 10^{5}

Sum of

N

over all test cases does not exceed

3 \cdot 10^{5}

Sum of

M

over all test cases does not exceed

3 \cdot 10^{5}

Sample Input 1

2
4 2
?ab?
ba
4 2
a??b
ab

Sample Output 1

aabe
-1

Explanation

Test case $1$

: Replace the

?

at indices

1

and

4

using characters

a

and

e

respectively. Both the characters belong to the set

{a, b, c, d, e}

.
The string

S^{'} = aabe

. Note that no subsequence of

S^{'}

is equal to

ba

Test case $2$

: There is no possible value of

S^{'}