Please solve the programming task below using a self-contained code snippet in a markdown code block.

There is a row of n houses, where each house can be painted one of three colors: red, blue, or green. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two adjacent houses have the same color.
The cost of painting each house with a certain color is represented by an n x 3 cost matrix costs.

For example, costs[0][0] is the cost of painting house 0 with the color red; costs[1][2] is the cost of painting house 1 with color green, and so on...

Return the minimum cost to paint all houses.
 
Please complete the following python code precisely:
```python
class Solution:
    def minCost(self, costs: List[List[int]]) -> int:
```