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CF1700B.Palindromic Numbers
Palindromic Numbers
During a daily walk Alina noticed a long number written on the ground. Now Alina wants to find some positive number of same length without leading zeroes, such that the sum of these two numbers is a palindrome.
Recall that a number is called a palindrome, if it reads the same right to left and left to right. For example, numbers are palindromes, and are not palindromes.
Alina understands that a valid number always exist. Help her find one!
Input
The first line of input data contains an integer () — the number of test cases. Next, descriptions of test cases follow.
The first line of each test case contains a single integer () — the length of the number that is written on the ground.
The second line of contains the positive -digit integer without leading zeroes — the number itself.
It is guaranteed that the sum of the values over all test cases does not exceed .
Output
For each of test cases print an answer — a positive -digit integer without leading zeros, such that the sum of the input integer and this number is a palindrome.
We can show that at least one number satisfying the constraints exists. If there are multiple solutions, you can output any of them.
Note
In the first test case is a palindrome. Note that another answer is , because is also a palindrome.
In the second test case .
In the third test case .
Samples
3
2
99
4
1023
3
385
32
8646
604
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