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>
ans = 0
fact = {}
ans = 0
originalVal = 1
largest = {}


# (originalVal,0,1)
def recurse(cur,ansSoFar,valueSoFar):
	# print cur,ansSoFar,valueSoFar
	global ans
	global originalVal
	if valueSoFar > originalVal:
		return
	if valueSoFar == originalVal:
		ans = max(ans,ansSoFar)
		return
	else :
		for x in xrange(2,10):
			if cur % fact[x] == 0:
				recurse(cur/fact[x],ansSoFar*10 + x,valueSoFar*fact[x])
		return

fact[1] = 1
fact[0] = 1
for x in xrange(2,10):
	fact[x] = fact[x-1]*x
largest[1] = 1
for x in xrange(2,10):
	originalVal = fact[x]
	ans = 0
	recurse(originalVal,0,1)
	largest[x] = ans
	# print largest[x],
# print

n = raw_input()
digitString = raw_input()
digits = list(digitString)

answer = ''

for x in digits:
	if int(x) not in  [0,1]:
		answer += str(largest[int(x)])
print ''.join(sorted(answer))[::-1]