Lookup result: 83;#Lastname, Firstname. How do I get rid of the \83;#\" at the beginning of the returned value?"

Hello! I have a Caculated Value field that retrieves a value, from another list, with this formula: lookup(“ContOB”, “RefID”, RefID, “Manager”) .It does get the correct Manager name but in this format: 83;#Lastname, Firstname. How do I get rid of the "83;#" at the beginning of the returned value?