 3

# Odd To Even

Difficulty: EASY
Avg. time to solve
10 min
Success Rate
90%

Problem Statement
Suggest Edit

#### You are given an odd number in the form of a string, ‘S.’ Your goal is to convert the number into an even number such that the following two conditions are satisfied.

``````You can use swap operation over any two indices i,e you can choose two indices 'i' and 'j' and swap the digits present at S[i] and S[j]. But this operation can be used only once.

Your final even number should be the largest out of all other possible even numbers.
``````
##### Note:
``````If it isn’t possible to make an even number print -1
``````
##### Input Format:
``````The first line of the input contains ‘T’ denoting the number of test cases.

The first and the only line of each test case contains a string ‘S’ the odd number.
``````
##### Output Format:
``````If it is possible to make even number print largest out of all. Else print -1

Print the result of each test case in a new line.
``````
##### Constraints:
``````1 <= T <= 5
0 <= |S| <= 10^5

Time Limit : 1 sec
``````
##### Sample Input 1:
``````3
652345
79345
31179
``````
##### Sample Output 1:
``````655342
79354
-1
``````
##### Explanation For Sample Input 1:
``````In test case 1:

552346, 655342, 652354 are the all possible even number which can be made by only using 1 swap operation.

Out of which 655342 is the largest, hence the answer.

In test case 2:
The only possible even number is 79354.

In test case 3:
There is no possible way to swap two digits to make the number even.
``````
##### Sample Input 2:
``````2
635875915
64966689669
``````
##### Sample Output 2:
``````635575918
94966689666
``````   Console