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>
n = input()
a = raw_input()

def f(s):
    s=int(s)
    if s==1 or s==0:
        return [0,0,0,0]
    if s==2:
        return [1,0,0,0]
    if s==3:
        return [1,1,0,0]
    if s==4:
        return [3,1,0,0]
    if s==5:
        return [3,1,1,0]
    if s==6:
        return [4,2,1,0]
    if s==7:
        return [4,2,1,1]
    if s==8:
        return [7,2,1,1]
    if s==9:
        return [7,4,1,1]

fac = [0,0,0,0]
for i in a:
    x = f(i)
    for i in range(4):
        fac[i] +=x[i]
n7 = fac[3]
n5 = fac[2]-n7
n3 = fac[1]-2*n7-n5
n2 = fac[0]-4*n7-3*n5-n3
print "7"*n7+"5"*n5+"3"*n3+"2"*n2
