Base Offering Circular - Multifamily 482090 79 product of (i) the original principal amount of the Ginnie Mae Multifamily Certificate and (ii) the Adjusted Certificate Factor for the preceding Special Excess Distribution Date exceeds (b) the product of (i) the original principal amount of the Ginnie Mae Multifamily Certificate and (ii) the Certificate Factor, Corrected Certificate Factor or Calculated Certificate Factor, as applicable, for the current Distribution Date; and (III) with respect to each Underlying Certificate (or Underlying Callable Security), the amount by which (a) the product of (i) the original principal amount of that Underlying Certificate (or Underlying Callable Security) and (ii) the Underlying Certificate Factor (or Certificate Factor) for the preceding Distribution Date exceeds (b) the product of (i) the original principal amount of the Underlying Certificate (or Underlying Callable Security) and (ii) the Underlying Certificate Factor (or Certificate Factor) for the current Distribution Date; provided however, that the amount calculated pursuant to clause (III) is subject to adjustment pursuant to the applicable Trust Agreement in the event that Underlying Certificate Factors (or Certificate Factors) are unavailable in respect of any Distribution Date.  (For the first Distribution Date, the product in clause (I)(a), (II)(a) and III(a) above shall be the principal amount of the Ginnie Mae Multifamily Certificate as of the Closing Date.)  The sum of the amounts so calculated for each Ginnie Mae Multifamily Certificate conveyed to a Trust for a Series (or, if the Series is segregated into Security Groups, for each Ginnie Mae Multifamily Certificate included in the related Trust Asset Group) is the Principal Distribution Amount for that Series (or Security Group(s)). With respect to each Callable Series and each Distribution Date and, in the case of a Callable Series that has more than one Security Group, each such Security Group, the amount by which (a) the product of (i) the original principal amount of the related Trust MBS and (ii) the Certificate Factor for the preceding Distribution Date exceeds (b) the product of (i) the original principal amount of the related Trust MBS and (ii) the Certificate Factor for the current Distribution Date; provided however, that (i) such amount shall be reduced by the principal portion of any related Trustee Fee; and (ii) such amount is subject to adjustment pursuant to Section 3.04 of the Standard Trust Provisions for Callable Trusts in the event that Certificate Factors are unavailable in