Swap Adjacent Nibbles

You are given a non-negative integer x, viewed as a 32-bit value (8 nibbles, including leading zeros). A nibble is a group of 4 bits, one hexadecimal digit.

Swap every adjacent nibble pair: the 1st with the 2nd, the 3rd with the 4th, and so on. Return the resulting value.

Examples

Example 1

Input: x = 305419896
Output: 558065031
Explanation: 305419896 is 0x12345678. Swapping adjacent hex digits pairwise gives 1 2 | 3 4 | 5 6 | 7 8 → 2 1 | 4 3 | 6 5 | 8 7, i.e. 0x21436587 = 558065031.

Example 2

Input: x = 1
Output: 16
Explanation: 0x00000001 → 0x00000010. The leading zero nibble swaps with the 1.