（AMC 2017 Question \#24）  In this year of 2017, my family is $in  its  prime$: I am 7, my brother is 5, my mother is 29 and my father is 31. All of our ages are prime numbers.  What is my father\textquotesingle{} s age the next year that my family is $in  its  prime$, when all of our ages are again prime? 
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