Given a string text, determine the length of the longest substring that contains no more than 2 different characters.

Examples:

Example 1:
Input: "abaccc"
Output: 4
Explanation: The answer is "accc", which has length 4.

Example 2:
Input: "bbaaac"
Output: 5
Explanation: The answer is "bbaaa", which has length 5.

Example 3:
Input: "deeeeef"
Output: 6
Explanation: The answer is "eeeeef", which has length 6.

Constraints:

• 1 <= text.length <= 20,000
• text consists of English letters.