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