list1 = []
list2 = []
str = input().split()
a,b = int(str[0]),int(str[1])
for i in range(a,b+1):
   flag = 0
   for j in range(2,i):
       if i%j == 0:
           flag = 1
           break
   if flag == 0:
       list1.append(i)
for i in list1:
   m = i
   sum = 0
   while(m):
       sum = m%10+sum*10
       m = m//10
   if i == sum:
       list2.append(i)
for i in list2:
   print(i)