Given the binary representation of an integer as a string `s`, return the number of steps to reduce it to `1` under the following rules:

- If the current number is even, you have to divide it by `2`.

- If the current number is odd, you have to add `1` to it.

It is guaranteed that you can always reach one for all test cases.

Example 1:

    Input: s = "1101"
    Output: 6
    Explanation: "1101" corressponds to number 13 in their decimal representation.
    Step 1) 13 is odd, add 1 and obtain 14.
    Step 2) 14 is even, divide by 2 and obtain 7.
    Step 3) 7 is odd, add 1 and obtain 8.
    Step 4) 8 is even, divide by 2 and obtain 4.
    Step 5) 4 is even, divide by 2 and obtain 2.
    Step 6) 2 is even, divide by 2 and obtain 1.

Example 2:

    Input: s = "10"
    Output: 1
    Explanation: "10" corressponds to number 2 in their decimal representation.
    Step 1) 2 is even, divide by 2 and obtain 1.

Example 3:

    Input: s = "1"
    Output: 0

Constraints:

- `1 <= s.length <= 500`
- `s` consists of characters '0' or '1'
- `s[0] == '1'`