You are given two strings `a` and `b` of the same length. Choose an index and split both strings at the same index, splitting `a` into two strings: `aprefix` and `asuffix` where `a = aprefix + asuffix`, and splitting `b` into two strings: `bprefix` and `bsuffix` where `b = bprefix + bsuffix`. Check if `aprefix + bsuffix` or `bprefix + asuffix` forms a palindrome.

When you split a string `s` into `sprefix` and `ssuffix`, either `ssuffix` or `sprefix` is allowed to be empty. For example, if `s = "abc"`, then `"" + "abc"`, `"a" + "bc"`, `"ab" + "c"` , and `"abc" + ""` are valid splits.

Return `true` if it is possible to form a palindrome string, otherwise return `false`.

Notice that `x + y` denotes the concatenation of strings `x` and `y`.

Example 1:

    Input: a = "x", b = "y"
    Output: true
    Explaination: If either a or b are palindromes the answer is true since you can split in the following way:
    aprefix = "", asuffix = "x"
    bprefix = "", bsuffix = "y"
    Then, aprefix + bsuffix = "" + "y" = "y", which is a palindrome.

Example 2:

    Input: a = "xbdef", b = "xecab"
    Output: false

Example 3:

    Input: a = "ulacfd", b = "jizalu"
    Output: true
    Explaination: Split them at index 3:
    aprefix = "ula", asuffix = "cfd"
    bprefix = "jiz", bsuffix = "alu"
    Then, aprefix + bsuffix = "ula" + "alu" = "ulaalu", which is a palindrome.

Constraints:

- `1 <= a.length, b.length <= 105`
- `a.length == b.length`
- `a` and `b` consist of lowercase English letters