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():
	from sys import stdin,stdout
if __name__=='__main__':
	main()
'''
#Journey to moon
'''
def main():
	from sys import stdin,stdout
	import collections
	N,I =map(int,stdin.readline().split())
	visited=list(0 for x in range(N))
	G=collections.defaultdict(list)
	groups=[0]
	for _ in range(I):
		a,b=map(int,stdin.readline().split())
		G[a].append(b)
		G[b].append(a)
	q=collections.deque()
	flag=0
	for i in range(N):
		if not visited[i]:
			q.append(i)
			visited[i]=flag+1
			groups[flag]+=1
			while len(q):
				top=q.popleft()
				for j in G[top]:
					if visited[j]!=visited[top]:
						visited[j]=flag+1
						groups[flag]+=1
						q.append(j)
			flag+=1
			groups.append(0)
	counter=0
	for i in range(len(groups)-1):
		for j in range(i+1,len(groups)):
			counter+=groups[i]*groups[j]
	stdout.write(str(counter))
if __name__=='__main__':
	main()
'''
#Djikstra's
'''
import collections
class Graph:
	def __init__(self):
		self.nodes=set()
		self.edges=collections.defaultdict(list)
		self.distances = {}

	def add_node(self, value):
		self.nodes.add(value)

	def add_edge(self, from_node, to_node, distance):
		self.edges[from_node].append(to_node)
		self.edges[to_node].append(from_node)
		self.distances[(from_node, to_node)] = distance
		self.distances[(to_node, from_node)] = distance


def dijsktra(graph, initial):
	visited = {initial: 0}
	path = {}

	nodes = set(graph.nodes)

	while nodes:
		min_node = None
		for node in nodes:
			if node in visited:
				if min_node is None:
					min_node = node
				elif visited[node] < visited[min_node]:
					min_node = node

		if min_node is None:
			break

		nodes.remove(min_node)
		current_weight = visited[min_node]

		for edge in graph.edges[min_node]:
			weight = current_weight + graph.distances[(min_node, edge)]
			if edge not in visited or weight < visited[edge]:
				visited[edge] = weight
				path[edge] = min_node

	return visited, path

def main():
	from sys import stdin,stdout
	for _ in range(int(stdin.readline())):
		n,m=map(int,stdin.readline().split())
		G=Graph()
		for i in range(n):
			G.add_node(i+1)
		for i in range(m):
			a,b,c=map(int,stdin.readline().split())
			G.add_edge(a,b,c)
		initial=int(stdin.readline())
		v,p=dijsktra(G, initial)
		#print(v)
		#print(p)
		for i in range(1,n+1):
			if i!=initial:
				k=v.get(i,-1)
				stdout.write(str(k)+' ')
		stdout.write('\n')
if __name__=='__main__':
	main()
'''
#Larget pallindrome in String
'''
def main():
	from sys import stdin,stdout
	string=stdin.readline().strip()
	l=len(string)
	#Triangle logic	
	
	arrlen=(l*(l-1))//2
	arr=list(0 for x in range(arrlen))
	f=0
	c=l-1
	for i in range(l-1):
		for j in range(i+1,l):
			if string[i]==string[j]:
				arr[f+j-i-1]=1
		f+=c
		c-=1
	#print(arr)
	if any(arr):
		
	else:
		if l & 1:
			stdout.write('First')
		else:
			stdout.write('Second')
	#2-d Array Logic
	arr=list(list(0 for i in range(l)) for j in range(l))
	for i in range(l):
		for j in range(l):
			if string[i]==string[j]:
				arr[i][j]=1
	maxim=0
	for i in range(0,l*(l-1)-2,l+1):
		a,b=i+1,i+2
		#print(a,b)
		acount=0
		x=a//5
		y=a%5
		acount=arr[x][y]		
		x-=1
		y-=1
		while x>=0 and y>=0:
			acount+=arr[x][y]
			x-=1
			y-=1
		x=b//5
		y=b%5
		bcount=arr[x][y]		
		x-=1
		y-=1
		while x>=0 and y>=0:
			bcount+=arr[x][y]
			x-=1
			y-=1
		maxim=max((acount,bcount,maxim))
	maxim=max(maxim,arr[l-2][l-1])
	maxim=(maxim<<1)^1
	delta=l-maxim
	if delta & 1:
		stdout.write('Second')
	else:
		stdout.write('First')
if __name__=='__main__':
	main()
'''
#276B
'''
def main():
	from sys import stdin,stdout
	import collections
	s=stdin.readline().strip()
	count=collections.Counter(s)
	l=list(filter(lambda x: count[x] & 1,list(x for x in count)))
	removed=sum(list(count[x] for x in l))-max(list(count[x] for x in l)+[0])
	if removed & 1:
		stdout.write('Second')
	else:
		stdout.write('First')
if __name__=='__main__':
	main()
'''
#362B
'''
def main():
	from sys import stdin,stdout
	n,m=map(int,stdin.readline().split())
	if m:
		dirty=sorted(map(int,stdin.readline().split()))
		if dirty[0]==1 or dirty[-1]==n:
			stdout.write('NO')
		else:
			flag=True
			for i in range(m-2):
				if dirty[i+1]==dirty[i]+1 and dirty[i+2]==dirty[i]+2:
					flag=False
					break
			if flag:
				stdout.write('YES')
			else:
				stdout.write('NO')
	else:
		stdout.write('YES')
if __name__=='__main__':
	main()
'''
#279B SUM OF SUB-ARRAY
'''
def main():
	from sys import stdin,stdout
	n,t=map(int,stdin.readline().split())
	arr=list(map(int,stdin.readline().split()))
	maxim=0
	curr_sum=arr[0]
	i=0
	j=1
	if curr_sum <=t:
		count=1
	else:
		curr_sum=0
		count=0
		i=1
		j=2
	while j<n:
		if curr_sum+arr[j]<=t:
			count+=1
			curr_sum+=arr[j]
			j+=1
		else:
			maxim=max(count,maxim)
			if curr_sum:
				curr_sum-=arr[i]
				count-=1
			else:
				j+=1
			i+=1
	maxim=max(count,maxim)
	stdout.write(str(maxim))
if __name__=='__main__':
	main()
'''
#469B
'''
def main():
	from sys import stdin,stdout
	p,q,l,r=map(int,stdin.readline().split())
	a=[]
	b=[]
	visited=list(0 for x in range(r-l+1))
	#print(visited)	
	for i in range(p):
		x,y=map(int,stdin.readline().split())
		a.append(x)
		b.append(y)
	for i in range(q):
		x,y=map(int,stdin.readline().split())
		x+=l
		y+=l
		for j in range(p):
			#print('x=',x,'y=',y)
			lower=max(0,a[j]-y)
			upper=min(b[j]-x,r)+1
			if upper > lower:
				delta=upper-lower
				#print('upper=',upper,'lower=',lower)
				visited[lower:upper]=list(1 for x in range(delta))
				#print('visited:\n',visited)
	#	print(visited)
	stdout.write(str(visited[:r-l+1].count(1)))
if __name__=='__main__':
	main()
'''
'''
def main():
	from sys import stdin,stdout
	#import numpy as np
	n,k=map(int,stdin.readline().split())
	a=tuple(map(int,stdin.readline().split()))
	minim=min(a)
	maxim=max(a)
	arr=list(a)	
	for i in range(n):
		arr[i]-=minim
	if max(arr) > k:
		stdout.write('NO')
	else:
		stdout.write('YES\n')
		for i in a:
			stdout.write('1 '*minim)
			for j in range(i-minim):
				stdout.write(str(j%k+1)+' ')
			stdout.write('\n')
if __name__=='__main__':
	main()
'''
'''
def main():
	from sys import stdin,stdout
	n,p=[],[]
	for _ in range(int(stdin.readline())):
		last=int(stdin.readline())
		if last<0:
			n.append(-1*last)
		else:
			p.append(last)
	if sum(p)>sum(n):
		stdout.write('first')
	elif sum(n)>sum(p):
		stdout.write('second')
	else:
		maxim=max(n,p)
		#print(maxim)
		if maxim==p:
			if maxim==n:
				if last<0:
					stdout.write('second')
				else:
					stdout.write('first')
			else:
				stdout.write('first')
		else:
			stdout.write('second')
		
if __name__=='__main__':
	main()
'''
#286C
'''
def main():
	from sys import stdin,stdout
	m,n=map(int,stdin.readline().split())
	minim=min(m,n)
	stdout.write(str(minim+1)+'\n')
	if n==minim:
		for i in range(minim+1):
			stdout.write(str(m)+' '+str(i)+'\n')
			m-=1
	else:
		for i in range(minim+1):
			stdout.write(str(i)+' '+str(n)+'\n')
			n-=1
if __name__=='__main__':
	main()
'''
#387B
'''
def main():
	from sys import stdin,stdout
	n,m=map(int,stdin.readline().split())
	a=tuple(map(int,stdin.readline().split()))
	b=tuple(map(int,stdin.readline().split()))
	i=0
	j=0
	while True:
		#print(i,j)
		if i>=n or j>=m:
			break
		if b[j]>=a[i]:
			i+=1
			j+=1
		else:
			j+=1
	stdout.write(str(n-i))
if __name__=='__main__':
	main()
'''
#365B
'''
def main():
	from sys import stdin,stdout
	n=int(stdin.readline())
	a=tuple(map(int,stdin.readline().split()))
	maxim=2
	count=2
	i=2
	while True:
		if i>=n:
			break
		if a[i]==a[i-1]+a[i-2]:
			count+=1
			maxim=max(count,maxim)
		else:
			count=2
		i+=1
	stdout.write(str(min(maxim,n)))
if __name__=='__main__':
	main()
'''	#474D
'''
def main():
	from sys import stdin,stdout
	MOD=int(1e9)+7
	T,k=map(int,stdin.readline().split())
	fib=[x for x in range(1,k+1)]
	for i in range(k,100001):
		fib.append((fib[i-1]+fib[i-k]+1)%MOD)
	for _ in range(T):
		a,b=map(int,stdin.readline().split())
		stdout.write(str((fib[b]-fib[a-1])%MOD)+'\n')
if __name__=='__main__':
	main()
'''
#330B
#not working
'''
def main():
	from sys import stdin,stdout
	import collections
	road_not=collections.defaultdict(set)
	n,m=map(int,stdin.readline().split())
	for _ in range(m):
		a,b=map(int,stdin.readline().split())
		road_not[a].add(b)
		road_not[b].add(a)
	counter=0
	road=collections.defaultdict(set)
	visited=[0 for x in range(n)]
	visited[0]=True
	for index in range(1,n+1):
		for i in range(1,n+1):
			if not visited[i-1]:
				if i not in road_not[index] and i!=index:
					counter+=1
					road[index].add(i)
					visited[i-1]=True
	stdout.write(str(counter)+'\n')
	for i in road:
		for j in road[i]:
			stdout.write(str(i)+' '+str(j)+'\n')
if __name__=='__main__':
	main()
'''
#208D
'''
def main():
	from sys import stdin,stdout
	import bisect
	n=int(stdin.readline())
	p=tuple(map(int,stdin.readline().split()))
	P=tuple(map(int,stdin.readline().split()))
	record=[0 for x in range(5)]
	points=0
	for i in p:
		points+=i
		while points>=P[0]:
			index=bisect.bisect_right(P,points)
			if index:
				index-=1
				number=points//P[index]
				record[index]+=number
				points-=P[index]*number
	for i in record:
		stdout.write(str(i)+' ')
	stdout.write('\n'+str(points))
if __name__=='__main__':
	main()
'''
#339D Using Al.Cash's Segment Trees
#Segment Tree
#not-working
'''
powers=1
t=[0 for x in range(3*int(1e5))]
def build(n):
	global t,powers
	flag=False
	for i in range(n-1,0,-1):
		if i==powers-1:
			flag=not flag
			powers>>=1
		if flag:
			t[i]=t[i<<1]^t[i<<1|1]
		else:
			t[i]=t[i<<1]|t[i<<1|1]

def modify(i,v,n):
	global t
	flag=False
	if t[i+n-1]==v or v|t[(i+n-1)^1]==t[(i+n-1)>>1]:
		#print('skipped')
		#print('t[i+n-1]=',t[i+n-1],'v=',v)
		#print('v|t[(i+n-1)^1]=',v|t[(i+n-1)^1],'t[(i+n-1)>>1]',t[(i+n-1)>>1])		
		t[i+n-1]=v		
		return
	t[i+n-1]=v
	p=i+n-1
	while p>1:
		if flag:
			if t[p>>1]==t[p]^t[p^1]:
				break
			t[p>>1]=t[p]^t[p^1]
			flag=not flag
		else:
			if t[p>>1]==t[p]|t[p^1]:
				break
			t[p>>1]=t[p]|t[p^1]
			flag=not flag
		p>>=1

def main():
	from sys import stdin,stdout
	global t,powers
	n,m=map(int,stdin.readline().split())
	p=tuple(map(int,stdin.readline().split()))
	powers=1<<(n-1)	
	n=1<<(n)	
	for i in range(n):
		t[i+n]=p[i]
	build(n)
	#print(t[:2*n])
	for _ in range(m):
		a,b=map(int,stdin.readline().split())
		modify(a,b,n)
		#print(t[:2*n])
		stdout.write(str(t[1])+'\n')
if __name__=='__main__':
	main()
'''
#330B
'''
def main():
	from sys import stdin,stdout
	n,m=map(int,stdin.readline().split())
	start_not=set()
	for _ in range(m):
		a,b=map(int,stdin.readline().split())
		start_not.add(a-1)
		start_not.add(b-1)
	visited=[False for _ in  range(n)]
	for i in range(n):
		if i not in start_not:
			center=i
			break
	stdout.write(str(n-1)+'\n')
	for i in range(n):
		if i != center:
			stdout.write(str(center+1)+' '+str(i+1)+'\n')
if __name__=='__main__':
	main()
'''
#116B
'''
def main():
	from sys import stdin,stdout
	n,m=map(int,stdin.readline().split())
	arr=[]
	for _ in range(n):
		arr.append(stdin.readline().strip())
	pigs=set()
	count=0
	for i in range(n):
		for j in range(m):
			if arr[i][j]=='W':
				flag=0
				if i>0:
					if arr[i-1][j]=='P':
						pigs.add((i-1,j))
						flag=1
				if i<n-1:
					if arr[i+1][j]=='P':
						pigs.add((i+1,j))
						flag=1
				if 	j>0:
					if arr[i][j-1]=='P':
						pigs.add((i,j-1))
						flag=1
				if j<m-1:
					if arr[i][j+1]=='P':
						pigs.add((i,j+1))
						flag=1
				if flag:
					count+=1
	stdout.write(str(min(len(pigs),count)))
if __name__=='__main__':
	main()
'''
#339D using Al.Cash's Segment Tree Implementation
'''
def main():
	from sys import stdin,stdout
	answers=()
	n,m=map(int,stdin.readline().split())
	p=tuple(map(int,stdin.readline().split()))
	powers=1<<(n-1)
	n=powers<<1
	t=[0 for _ in range(n<<1)]
	for i in range(n):
		t[n+i]=p[i]
	flag=False
	for i in range(n-1,0,-1):
		if i==powers-1:
			flag=not flag
			powers>>=1
		if flag:
			t[i]=t[i<<1]^t[i<<1|1]
		else:
			t[i]=t[i<<1]|t[i<<1|1]
	for _ in range(m):
		a,b=map(int,stdin.readline().split())
		flag=False
		if t[a+n-1]==b or b|t[(a+n-1)^1]==t[(a+n-1)>>1]:
			t[a+n-1]=b
		else:
			t[a+n-1]=b
			p=a+n-1
			while p > 1:
				if flag:
					if t[p>>1]==t[p]^t[p^1]:
						break
					t[p>>1]=t[p]^t[p^1]
					flag=not flag
				else:
					if t[p>>1]==t[p]|t[p^1]:
						break
					t[p>>1]=t[p]|t[p^1]
					flag= not flag
				p>>=1
		stdout.write(str(t[1])+'\n')
if __name__=='__main__':
	main()
'''
#515C
def main():
	from sys import stdin,stdout
	import collections
	nc=[0 for x in range(10)]
	n=int(stdin.readline())
	num=stdin.readline().strip()
	for i in num:
		k=int(i)
		if k==9:
			nc[7]+=1
			nc[3]+=2
			nc[2]+=1
		elif k==8:
			nc[7]+=1
			nc[2]+=3
		elif k==7:
			nc[7]+=1
		elif k==6:
			nc[5]+=1
			nc[3]+=1
		elif k==5:
			nc[5]+=1
		elif k==4:
			nc[3]+=1
			nc[2]+=2
		elif k==3:
			nc[3]+=1
		elif k==2:
			nc[2]+=1
	ans=''
	for i in range(10):
		ans+=str(9-i)*nc[9-i]
	stdout.write(ans)		
if __name__=='__main__':
	main()
