An old man while dialing a 7 digit telephone humber remembcrs that the first four digits consists of one I's, one 2's and two 3's. He also remembers that the fifth digit is cither a 4 or 5 while has no memorising of the sixth digit, he remembers that the seventh digit is 9 minus the sixth digit. Maximum number of distinet trials he has to try to make sure that he dials the correct telephone number, is