Given two strings text1 and text2, return the length of the longest common subsequence between the two strings if one exists, otherwise return 0.

A subsequence is a sequence that can be derived from the given sequence by deleting some or no elements without changing the relative order of the remaining characters.

• For example, "cat" is a subsequence of "crabt".

A common subsequence of two strings is a subsequence that exists in both strings.

Example 1:

Input: text1 = "cat", text2 = "crabt" 

Output: 3 

Explanation: The longest common subsequence is "cat" which has a length of 3.

Example 2:

Input: text1 = "abcd", text2 = "abcd"

Output: 4

Example 3:

Input: text1 = "abcd", text2 = "efgh"

Output: 0

Constraints:

• 1 <= text1.length, text2.length <= 1000
• text1 and text2 consist of only lowercase English characters.