Return the sum of all integers in `nums`. Variant **#18** focuses on clean iteration without built-in shortcuts.
Example 1
Input: nums = [18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39]
Output: 627
Constraints
Acceptance: 63% · Topics: array, math