Two terms total are allowed:
"Section 1. No person shall be elected to the office of the President more than twice, and no person who has held the office of President, or acted as President, for more than two years of a term to which some other person was elected President shall be elected to the office of the President more than once."
The second provision applies to something like a Gerald Ford scenario.
"To speak ill of others is a dishonest way of praising ourselves"