Here is my code:
I used python for this question.

```
import sys
import math

t = input()
lst = []
for i in range(0, len(t), 2):
    lst.append(t[i+1])
    lst.append(t[i])

answer = "".join(lst)
print(answer)

```

1. `Input 1 : 01ABxy Output: 10BAyx`

However, my program only works with index with even numbers, when I try plug something like this:

2. `Input 2: ReadabilityCounts Output: The index out of range.`