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

Given two strings text1 and text2, return the length of their longest common subsequence. If there is no common subsequence, return 0.
A subsequence of a string is a new string generated from the original string with some characters (can be none) deleted without changing the relative order of the remaining characters.

For example, "ace" is a subsequence of "abcde".

A common subsequence of two strings is a subsequence that is common to both strings.
 
Please complete the following python code precisely:
```python
class Solution:
    def longestCommonSubsequence(self, text1: str, text2: str) -> int:
```