Consider this challenge: 

> 
> Given two numbers `A` and `B`, in how many ways you can select `B` distinct primes, where each of the primes should be less than or equal to `A` (`<= A`). Since the number can be large, provide your answer mod 65537.
> 
> 
> 

For example 

If `A = 7` and `B = 2`, then:  

All primes `<= A` are `{2, 3, 5, 7}`, and the answer will be `6`: `{2, 3} {2, 5} {2, 7} {3, 5} {3, 7} {5, 7}`

I have created this solution:

```
from math import factorial
from math import fmod 

def nPk(n,k):
    return int( factorial(n)/factorial(n- k))  

def is_prime(a):
    for i in range(2,a):
        if a % i ==0:
            return False
    return True

def distinct_primes(A):
    primes = []
    for i in range(2,A):
        if is_prime(i):
            primes.append(i)
    return len(primes)

def fct(A, B):
    return nPk(distinct_primes(A),B)

#print fct(59,5)% 65537
print fmod(fct(69,8), 65537)

```

But, I am not getting the right answer! What am I missing here?