Given a string `path`, which is an absolute path (starting with a slash `'/'`) to a file or directory in a Unix-style file system, convert it to the simplified canonical path.

In a Unix-style file system, a period `'.'` refers to the current directory, a double period `'..'` refers to the directory up a level, and any multiple consecutive slashes (i.e. `'//'`) are treated as a single slash `'/'`. For this problem, any other format of periods such as `'...'` are treated as file/directory names.

The canonical path should have the following format:

- The path starts with a single slash `'/'`.
- Any two directories are separated by a single slash `'/'`.
- The path does not end with a trailing `'/'`.
- The path only contains the directories on the path from the root directory to the target file or directory (i.e., no period `'.'` or double period `'..'`)

Return the simplified canonical path.

Example 1:

    Input: path = "/home/"
    Output: "/home"
    Explanation: Note that there is no trailing slash after the last directory name.

Example 2:

    Input: path = "/../"
    Output: "/"
    Explanation: Going one level up from the root directory is a no-op, as the root level is the highest level you can go.

Example 3:

    Input: path = "/home//foo/"
    Output: "/home/foo"
    Explanation: In the canonical path, multiple consecutive slashes are replaced by a single one.

Constraints:

- `1 <= path.length <= 3000`
- `path` consists of English letters, digits, period `'.'`, slash `'/'` or `'_'`.
- `path` is a valid absolute Unix path.