from itertools import combinations_with_replacement as cp
from itertools import permutations as p
import gmpy2

def is_prime(num):
    return gmpy2.is_prime(num) if num > 0 else False

def get_total_primes(a, b):
    c=0
    for i in cp('2357',len(str(b))):
        q = int(''.join(i))
        if p in range(a,b) and is_prime(q):
            c+=1
    return c