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>

1^4 * 2^3 * 3^2 * 2^2

2^5 * 3^2 * 1

# 4 1234 = 1!*3!*2!*4!  332222
#  aaxa reorder(aaxa) <= n <= 2222222


# 2! = 2
# 3! = 3 * 2!  = 3! 
# 4! = 3! * 2! * 2! 
# 5! = 5!
# 6! = 3! * 5! 
# 7! = 7!
# 8! = 2! * 2! * 2! * 7!
# 9! = 3! * 3! * 2! * 7!
def get_facts_memo():
  memo = {}
  memo["2"] = [0,0,0,1]
  memo["3"] = [0,0,1,0]
  memo["4"] = [0,0,1,2]
  memo["5"] = [0,1,0,0]
  memo["6"] = [0,1,1,0]
  memo["7"] = [1,0,0,0]
  memo["8"] = [1,0,0,3]
  memo["9"] = [1,0,2,1]
  return memo


def sum_of_facts(a,b):
  c = []
  for i in range(0,4):
    c.append(a[i]+b[i])
  return c

def get_value(i):
  if i == 0:
    return "7"
  elif i == 1:
    return "5"
  elif i == 2:
    return "3"
  else:
    return "2"

def solve(digits):
  memo = get_facts_memo()
  result = [0]*4
  for digit in digits:
    if digit in memo:
      result = sum_of_facts(result, memo[digit])
  
  word = ""
  for i in range(0,4):
    value = get_value(i)
    for j in range(result[i]):
      word += value
  return word


n = int(input())
digits = input()
word = solve(digits)
print(word)