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 cf2():
    fr[2] = fr[2] + 1

def cf3():
    cf2()
    fr[3] = fr[3] + 1

def cf4():
    cf3()
    fr[2] = fr[2] + 2

def cf5():
    cf4()
    fr[5] = fr[5] + 1

def cf6():
    cf5()
    fr[2] = fr[2] + 1
    fr[3] = fr[3] + 1

def cf7():
    cf6()
    fr[7] = fr[7] + 1

def cf8():
    cf7()
    fr[2] = fr[2] + 3

def cf9():
    cf8()
    fr[3] = fr[3] + 2

def ad4():
    fr[2] = fr[2] - 2
    fr[4] = fr[4] + 1

def ad6():
    fr[2] = fr[2] - 1
    fr[3] = fr[3] - 1
    fr[6] = fr[6] + 1

fr = [0] * 10

n = int(input(""))
a = int(input(""))

acpy = a
for i in range(1, n + 1):
    x = int(acpy % 10)
    if x == 2:
        cf2()
    elif x == 3:
        cf3()
    elif x == 4:
        cf4()
    elif x == 5:
        cf5()
    elif x == 6:
        cf6()
    elif x == 7:
        cf7()
    elif x == 8:
        cf8()
    elif x == 9:
        cf9()
    acpy = acpy / 10

numar = ""
while fr[7] != 0:
    ad6()
    ad4()
    numar = numar + "7"
    for j in range (7, 1, -1):
        fr[j] = fr[j] - 1

while fr[5] != 0:
    ad4()
    numar = numar + "5"
    for j in range (5, 1, -1):
        fr[j] = fr[j] - 1

while fr[3] != 0:
    numar = numar + "3"
    fr[3] = fr[3] - 1
    fr[2] = fr[2] - 1

while fr[2] != 0:
    numar = numar + "2"
    fr[2] = fr[2] - 1

print(numar)