I have a difficult function to write and I have no idea where to begin. Here is the definition of what I need to write:

"A function f(x,y) which returns true if the binary number formed by concatenating the bits of x, 8*y-1 zeroes and a one is prime, false otherwise. x is an array of bytes (unsigned char) and y is an unsigned integer comprised of two bytes (unsigned short)."

EG:

f(10,1234)=isPrime(00001010...0x9871...1)

I am just completely lost as to what to do. I think there should be a better way than actually creating a class that can store massive numbers and than doing the traditional primality check of:

```
bool isPrime(myLargeIntegerMimic a)
{
for (myLargeIntegerMimic i=2; i*i<a; i++)
{
if (a%i==0)
return false;
}
return true;
}
```

Since myLargeIntegerMimic would have to store a massive array of 'y' bytes and then would have to successfully do multiplication and modulation on it, this would be extremely slow. I am hoping that I am missing some kind of short-cut.