Semi primes

Question

how to check if an integer can be expressed as a sum of two semi primes in c language?(examples: 30=15+15 and 45=35+10 as we see in this example 35,10,15 are semi prime)
(A semi prime number is an integer which can be expressed as a product of two distinct primes.
examples: 15=3*5)

Answer 1

bool isPrime(int n){...}
bool isSemiPrime(int n){...}
bool isSumOfSemiPrime(int n){...}

Answer 2

#scarlet I want logic/code for this only in c language.....so pls...