Problem:
Twin Prime

Prime numbers are widely applied for cryptographic and communication technology.
A twin prime is a prime number that differs from another prime number by 2.
For example, (5, 7) and (11, 13) are twin prime pairs.

In this problem, we call the greater number of a twin prime "size of the twin prime."

Your task is to create a program which reads an integer n and prints a twin prime which has the maximum size among twin primes less than or equals to n

You may assume that 5 ≤ n ≤ 10000.

Input

The input is a sequence of datasets. The end of the input is indicated by a line containing one zero. Each dataset is formatted as follows:

n (integer)

Output

For each dataset, print the twin prime p and q (p < q). p and q should be separated by a single space.

Sample Input

12
100
200
300
0

Output for the Sample Input

5 7
71 73
197 199
281 283

Solution in Python (judge verdict: Wrong Answer)

MN = 10000
tp = []
op = -5
mem = [False * 2] + [True] * MN
for i in range(2, MN):
  if not mem[i]:
    continue
  if i - op == 2:
    tp.append((op, i))
  op = i
  for j in range(i + i, MN, i):
    mem[j] = False

while True:
  N = input()
  if not N:
    break
  for i, p in enumerate(tp):
    if p[1] > N:
      print('%d %d' % (tp[i - 1][0], tp[i - 1][1]))
      break