Minimum Suffix Toggles

You are given a binary string target of length n. You also have a binary string s of length n that starts as all '0'.

Consider an operation where you choose an index i with 0 <= i < n and toggle every character of s from index i to index n - 1. Toggling changes '0' to '1' and '1' to '0'.

Given that you can perform this operation any number of times, return the minimum number of operations needed to make s equal to target.

Examples

Example 1

Input: target = "10111"
Output: 3
Explanation: Starting from "00000", toggle from index 0 to get "11111", toggle from index 1 to get "10000", toggle from index 2 to get "10111". Three operations are needed.

Example 2

Input: target = "101"
Output: 3
Explanation: Toggle from index 0 to get "111", from index 1 to get "100", and from index 2 to get "101".

Example 3

Input: target = "00000"
Output: 0
Explanation: `s` already equals `target`, so no operations are needed.