Given an integer array nums where every element appears three times except for one, which appears exactly once. Find the single element and return it.

You must implement a solution with linear runtime complexity and use only constant extra space.

Example 1:

Input:  2 2 3 2
Output: 3

Example 2:

Input:  0 1 0 1 0 1 99
Output: 99

Constraints:

• 1 ≤ nums.length ≤ 3 × 10⁴
• -2³¹ ≤ nums[i] ≤ 2³¹ - 1

Input format: Space-separated integers.

Output format: The single integer.