On a 2D plane, we place `n` stones at some integer coordinate points. Each coordinate point may have at most one stone.

A stone can be removed if it shares either the same row or the same column as another stone that has not been removed.

Given an array `stones` of length `n` where `stones[i] = [xi, yi]` represents the location of the `ith` stone, return the largest possible number of stones that can be removed.

Example 1:

    Input: stones = [[0,0],[0,1],[1,0],[1,2],[2,1],[2,2]]
    Output: 5
    Explanation: One way to remove 5 stones is as follows:
    1. Remove stone [2,2] because it shares the same row as [2,1].
    2. Remove stone [2,1] because it shares the same column as [0,1].
    3. Remove stone [1,2] because it shares the same row as [1,0].
    4. Remove stone [1,0] because it shares the same column as [0,0].
    5. Remove stone [0,1] because it shares the same row as [0,0].
    Stone [0,0] cannot be removed since it does not share a row/column with another stone still on the plane.

Example 2:

    Input: stones = [[0,0],[0,2],[1,1],[2,0],[2,2]]
    Output: 3
    Explanation: One way to make 3 moves is as follows:
    1. Remove stone [2,2] because it shares the same row as [2,0].
    2. Remove stone [2,0] because it shares the same column as [0,0].
    3. Remove stone [0,2] because it shares the same row as [0,0].
    Stones [0,0] and [1,1] cannot be removed since they do not share a row/column with another stone still on the plane.

Example 3:

    Input: stones = [[0,0]]
    Output: 0
    Explanation: [0,0] is the only stone on the plane, so you cannot remove it.

Constraints:

- `1 <= stones.length <= 1000`
- `0 <= xi, yi <= 104`
- No two stones are at the same coordinate point.