How to simplify quotient and mod in integer domain


I want to simplify (a*32 + a%32)/32, and a is integer.

So I write:

Simplify[Quotient[a*32 + Mod[a, 32], 32], Element[a, PositiveIntegers]] 

However it gives me:

Quotient[32 a + Mod[a, 32], 32] 

and I expect to see a