Given a string s consists of some words separated by spaces, return the length of the last word in the string. If the last word does not exist, return 0.
A word is a maximal substring consisting of non-space characters only.
Example 1:
Input: s = "Hello World" Output: 5
Example 2:
Input: s = " " Output: 0
Constraints:
1 <= s.length <= 104sconsists of only English letters and spaces' '.