# twins.py
# Fig 17.9 
# input: 1000000  1001000

import math
from prime import *

a,b = map(int, input("a b=? ").split())
x = 6*math.trunc(a/6) + 5
while x <= b-2:
  if isPrime(x) and isPrime(x+2):
    print(x, x+2)
  x += 6