Generate Palindrome

You are given an integer n. Your task is to generate a palindrome of length n by using only lowercase English letters. In this problem, you should generate a palindrome that consists solely of the letter 'a'.

If n is less than or equal to 0, output "-1".

For example:

• If n = 3, a valid palindrome is "aaa".
• If n = 4, a valid palindrome is "aaaa".
• If n <= 0, the output should be "-1".

The input consists of multiple test cases. For each test case, you are given an integer n on a separate line. You need to process each test case and print the corresponding palindrome on a new line.

inputFormat

The input is read from stdin and is structured as follows:

1. The first line contains an integer T representing the number of test cases.
2. The following T lines each contain a single integer n, the required length of the palindrome.

Note: There is no additional text in the input.

outputFormat

For each test case, print the generated palindrome on a new line to stdout. If n is less than or equal to 0, print "-1".

## sample

5
3
4
2
1
5

aaa
aaaa
aa
a
aaaaa

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