Python :

import math
def sx(x):
    f=0
    for i in range(2,int(math.sqrt(x))):
        if x%i==0:
            f=1
    if f==0:
        return(True)
    else:
        return(False)
sr=input()
sr=sr[0:len(sr)-1]
s=""
for i in range(0,len(sr)-1):
    a1=int(sr[i])
    a2=int(sr[i+1])
    a=a1*10+a2
    b=a2*10+a1
    if sx(a)==True and sx(b)==True:
        s=s+str(a)+","
print(s[0:len(s)-1])