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>
x = int(input())
y = input()
ct = {0:[0, 0, 0, 0], 1:[0, 0, 0, 0], 2:[1, 0, 0, 0], 3:[1, 1, 0, 0], 4:[3, 1, 0, 0], 5:[3, 1, 1, 0], 6:[4, 2, 1, 0], 7:[4, 2, 1, 1], 8:[7, 2, 1, 1], 9:[7, 4, 1, 1]}
real = {2:[1, 0, 0, 0], 3:[1, 1, 0, 0], 4:[3, 1, 0, 0], 5:[3, 1, 1, 0], 6:[4, 2, 1, 0], 7:[4, 2, 1, 1], 8:[7, 2, 1, 1], 9:[7, 4, 1, 1]}
ut = {2:[1, 0, 0, 0], 3:[1, 1, 0, 0], 5:[3, 1, 1, 0], 7:[4, 2, 1, 1]}
lx = [0, 0, 0, 0]
for i in y:
    i = int(i)
    bad = ct[i]
    lx[0] += bad[0]
    lx[1] += bad[1]
    lx[2] += bad[2]
    lx[3] += bad[3]

s = ''
if lx[-1] >= 1:
    copies = lx[-1]
    lx[0] -= 4*copies
    lx[1] -= 2*copies
    lx[2] -= copies
    lx[3] -= copies
    s += '7' * copies

if lx[-2] >= 1:
    copies = lx[-2]
    lx[0] -= 3*copies
    lx[1] -= copies
    lx[2] -= copies
    s += '5' * copies

if lx[-3] >= 1:
    copies = lx[-3]
    lx[0] -= copies
    lx[1] -= copies
    s += '3' * copies

if lx[-4] >= 1:
    copies = lx[-4]
    lx[0] -= copies
    s += '2' * copies


print(s)
