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 main():
    n = int(raw_input())
    s = raw_input()
    p = [2,3,5,7]
    x = [0 for i in xrange(8)]
    po = [[0 for i in xrange(10)] for j in xrange(10)]
    for i in xrange(4):
        y = p[i]
        for j in xrange(4):
            z = p[j]
            while y / z > 0:
                po[p[i]][p[j]] += y / z 
                z *= p[j]
    for i in xrange(n):
        y = ord(s[i]) - ord('0')
        if y != 1 and y != 0:
            for j in xrange(4):
                z = p[j]
                while y / z > 0:
                    x[p[j]] += y / z;
                    z *= p[j]
                #print yy,p[j],ctr
    #print x
    ans = []
    for i in xrange(3,-1,-1):
        for j in xrange(x[p[i]]):
            ans.append(p[i])
            for k in xrange(i-1,-1,-1):
                x[p[k]] -= po[p[i]][p[k]]
    print "".join(map(str,ans)) 
    return

if __name__ == '__main__':
    main()