human
Can you provide a the Python code you requested given the following:
I found an interesting problem on https://leetcode.com/problems/longest-common-subsequence/:
Given two strings text1 and text2, return the length of their longest common subsequence.
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. (eg, "ace" is a subsequence of "abcde" while "aec" is not). A common subsequence of two strings is a subsequence that is common to both strings.
 
If there is no common subsequence, return 0.
 
Example 1:
Input: text1 = "abcde", text2 = "ace" 
Output: 3  
Explanation: The longest common subsequence is "ace" and its length is 3.

Example 2:
Input: text1 = "abc", text2 = "abc"
Output: 3
Explanation: The longest common subsequence is "abc" and its length is 3.

Example 3:
Input: text1 = "abc", text2 = "def"
Output: 0
Explanation: There is no such common subsequence, so the result is 0.

 
Constraints:

1 <= text1.length <= 1000
1 <= text2.length <= 1000
The input strings consist of lowercase English characters only.

I tried it in Python, but could not do it. Can you solve it?
assistant
#Here is the Python code you requested.

class Solution:
    def lcs(self, s1, s2, m, n):
        if m == 0 or n == 0:
            return 0
        if self.dp[m][n] != -1: return self.dp[m][n]
        if s1[m - 1] == s2[n - 1]:
            self.dp[m][n] = 1 + self.lcs(s1, s2, m - 1, n - 1)
        else:
            self.dp[m][n] = max(self.lcs(s1, s2, m - 1, n), self.lcs(s1, s2, m, n - 1))
        return self.dp[m][n]

    def longestCommonSubsequence(self, text1: str, text2: str) -> int:
        m = len(text1)
        n = len(text2)
        self.dp = [[-1 for _ in range(n + 1)] for __ in range(m + 1)]
        return self.lcs(text1, text2, m, n)