Given a collection of intervals, find the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping.

**Note:**

- You may assume the interval's end point is always bigger than its start point.
- Intervals like [1,2] and [2,3] have borders "touching" but they don't overlap each other.

**Example 1:**

Input:[ [1,2], [2,3], [3,4], [1,3] ]

Output:1

Explanation:[1,3] can be removed and the rest of intervals are non-overlapping.

**Example 2:**

Input:[ [1,2], [1,2], [1,2] ]

Output:2

Explanation:You need to remove two [1,2] to make the rest of intervals non-overlapping.

**Example 3:**

Input:[ [1,2], [2,3] ]

Output:0

Explanation:You don’t need to remove any of the intervals since they’re already non-overlapping.