Battery Bar

The tablet starts the day full of promise. The apps have other plans. 🔋

You get the starting charge percent and the hourly usage amounts, in order. Print the hour number (1, 2, 3…) when the charge first hits 0 or below — or survived if it lasts through the whole list.

Example:

Input: charge = 100, usage = [30, 40, 20, 15] Output: 4

After each hour the charge is 70, 30, 10, -5 — it first drops to 0 or below on hour 4.