Given an integer array nums, find the contiguous subarray with the largest sum and return its sum.

Example 1:

Input: -2 1 -3 4 -1 2 1 -5 4
Output: 6
Explanation: [4,-1,2,1] has the largest sum = 6.

Example 2:

Input: 1
Output: 1

Constraints:

• 1 ≤ nums.length ≤ 10⁵
• -10⁴ ≤ nums[i] ≤ 10⁴

Input format: Space-separated integers.

Output format: Maximum subarray sum.