You are given a 0-indexed binary string `target` of length `n`. You have another binary string `s` of length `n` that is initially set to all zeros. You want to make `s` equal to `target`.

In one operation, you can pick an index `i` where `0 <= i < n` and flip all bits in the inclusive range `[i, n - 1]`. Flip means changing `'0'` to `'1'` and `'1'` to `'0'`.

Return the minimum number of operations needed to make `s` equal to `target`.

Example 1:

    Input: target = "10111"
    Output: 3
    Explanation: Initially, s = "00000".
    Choose index i = 2: "00000" -> "00111"
    Choose index i = 0: "00111" -> "11000"
    Choose index i = 1: "11000" -> "10111"
    We need at least 3 flip operations to form target.

Example 2:

    Input: target = "101"
    Output: 3
    Explanation: Initially, s = "000".
    Choose index i = 0: "000" -> "111"
    Choose index i = 1: "111" -> "100"
    Choose index i = 2: "100" -> "101"
    We need at least 3 flip operations to form target.

Example 3:

    Input: target = "00000"
    Output: 0
    Explanation: We do not need any operations since the initial s already equals target.

Constraints:

- `n == target.length`
- `1 <= n <= 105`
- `target[i]` is either `'0'` or `'1'`.