Contractor Warranty


I have a question:
I am aware depending on the Roof material used determines the # of years warranty by the manufacture. Although, what is the standard Contractor Warranty. Please help me by filling in the blanks (???).
Thanks and I really appreciated you help!

Shingles guaranteed under manufacturer’s warranty for a period of ??? year(s). Contractor’s warranty shall be limited to defects in workmanship within the scope of work performed by Contractor and which arise and become known within ??? year(s) from the date hereof. Contractor agrees to repair any roofing leaks under normally anticipated weather conditions. Ice damming is not a normally anticipated condition. Damage done to the roof system through no fault of the Contractor are not warranted by Contractor. All said defects arising after ??? year(s) and defects in material are not warranted by Contractor. Contractor hereby assigns to Owner all warranties on materials as provided by the manufacturer of such materials.****