Drazil is playing a math game with Varda.

Let's define <image> for positive integer x as a product of factorials of its digits. For example, <image>.

First, they choose a decimal number a consisting of n digits that contains at least one digit larger than 1. This number may possibly start with leading zeroes. Then they should find maximum positive number x satisfying following two conditions:

1. x doesn't contain neither digit 0 nor digit 1.

2. <image> = <image>.

Help friends find such number.

Input

The first line contains an integer n (1 ≤ n ≤ 15) — the number of digits in a.

The second line contains n digits of a. There is at least one digit in a that is larger than 1. Number a may possibly contain leading zeroes.

Output

Output a maximum possible integer satisfying the conditions above. There should be no zeroes and ones in this number decimal representation.

Examples

Input

4
1234


Output

33222


Input

3
555


Output

555

Note

In the first case, <image>
# 515C

__author__ = 'artyom'

# SOLUTION

def main():
  read()
  a, m = [], [[], [], [2], [3], [3, 2, 2], [5], [5, 3], [7], [7, 2, 2, 2], [7, 3, 3, 2]]
  for x in read(0):
    a.extend(m[int(x)])
  return list(reversed(sorted(a)))


# HELPERS


def read(mode=2):
  # 0: String
  # 1: List of strings
  # 2: List of integers
  inputs = input().strip()
  if mode == 0: return inputs
  if mode == 1: return inputs.split()
  if mode == 2: return int(inputs)
  if mode == 3: return list(map(int, inputs.split()))


def write(s="\n"):
  if s is None: s = ""
  if isinstance(s, list): s = "".join(map(str, s))
  s = str(s)
  print(s, end="")


write(main())