def pairConcPrime(x,y): s=str(x) t=str(y) if isPrime( int(s+t) ) and isPrime( int(t+s) ): return True#y else: return False#0
def isEightFamily(prime, repDig): p=str(prime) rd=str(repDig) c=0 for digit in '0123456789': n=int( replace(p,rd,digit) ) if isPrime(n) and n>10000: c+=1 if c==8: return True return False