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>
def Factorial ( n ) :
    if ( n == 0 ) :
        return 1
       
    res = 1
    
    for i in range ( 1, n + 1 ) :
        res *= i
    
    return res

m = { 2 : 0, 3 : 0, 5 : 0, 7 : 0 }

n = int ( raw_input () )
q = int ( raw_input () )

# print n, q

while ( q ) :
    c = q % 10
    
    # print c
    
    for i in range ( 1, c + 1 ) :
        if ( i == 2 ) :
            m [ 2 ] += 1
        elif ( i == 3 ) :
            m [ 3 ] += 1
        elif ( i == 4 ) :
            m [ 2 ] += 2
        elif ( i == 5 ) :
            m [ 5 ] += 1
        elif ( i == 6 ) :
            m [ 2 ] += 1
            m [ 3 ] += 1
        elif ( i == 7 ) :
            m [ 7 ] += 1
        elif ( i == 8 ) :
            m [ 2 ] += 3
        elif ( i == 9 ) :
            m [ 3 ] += 2 
    
    q /= 10

s = ""

# print "OK"

if ( m [ 7 ] > 0 ) :
    for i in range ( m [ 7 ] ) :
        m [ 2 ] -= 4
        m [ 3 ] -= 2
        m [ 5 ] -= 1
        s = s + "7"
     
if ( m [ 5 ] > 0 ) :
    for i in range ( m [ 5 ] ) :
        m [ 2 ] -= 3
        m [ 3 ] -= 1
        s += "5"

if ( m [ 3 ] > 0 ) :
    for i in range ( m [ 3 ] ) :
        m [ 2 ] -= 1
        s += "3"

if ( m [ 2 ] > 0 ) :
    for i in range ( m [ 2 ] ) :
        s += "2"

print s