Which number is missing in the white square?

A farmer named Muldoon lived alone in the Irish countryside except for a pet dog he for a long time.

The dog finally died and Muldoon went to the parish priest, saying "Father, the dog is dead. Could you possibly be saying a Mass for the poor creature?"

Father Patrick told the farmer "No, we can't have services for an animal in the church, but I'll tell you what, there's a new denomination down the road apiece, and no telling what they believe in, but maybe they'll do something for the animal."

Muldoon said "I'll go right now. By the way, do you think $50,000 is enough to donate for the service?"

Father Patrick replied "Why didn't you tell me the dog was Catholic."