Palindrome Pain

 You are given two integers 

X$X$ and Y$Y$. You need to construct two different strings S1$S_1$ and S2$S_2$ consisting of only the characters ‘a′$‘a^{\prime }$ and ‘b′$‘b^{\prime }$, such that the following conditions are satisfied:

1. Both S1$S_1$ and S2$S_2$ are palindromes.
2. Both S1$S_1$ and S2$S_2$ should contain exactly X$X$ occurrences of a$\mathtt{\text{a}}$ and Y$Y$ occurrences of b$\mathtt{\text{b}}$.

If there are multiple possible answers, you may print any of them. If it is not possible to construct two distinct strings satisfying the conditions, print −1$-1$ instead.

Input Format

• The first line of input will contain a single integer T$T$, denoting the number of test cases. Then the test cases follow.
• Each test case consists of a single line of input containing two space-separated integers X,Y$X,Y$.

Output Format

For each test case:

• If it is not possible to construct two distinct strings satisfying the conditions, print −1$-1$
• Otherwise, print two lines — the first should contain the string S1$S_1$ and the second should contain S2$S_2$
• If there are multiple possible answers, you may print any of them.

Constraints

• 1≤T≤1000$1\le T\le 1000$
• 1≤X,Y≤103$1\le X,Y\le {10}^3$

Sample Input 1 

2
2 4
3 3

Sample Output 1 

abbbba
babbab
-1

Explanation

Test case 1$1$: The three palindromes containing 2$2$ a$\mathtt{\text{a}}$-s and 4$4$ b$\mathtt{\text{b}}$-s are abbbba,babbab,$\mathtt{\text{abbbba}},\mathtt{\text{babbab}},$ and bbaabb$\mathtt{\text{bbaabb}}$. Printing any two of these is a valid answer.

Test case 2$2$: There are no palindromes containing 3$3$ each of a$\mathtt{\text{a}}$ and b$\mathtt{\text{b}}$.