#include<cstdio>

#include<iostream>

#include<algorithm>

#include<cstring>

#include<cmath>

#include<vector>

#include<queue>

#include<map>

#include<set>

#include<stack>

#include<cstdlib>

#include<string>

#include<bitset>

#define INF 100000000

#define fi first

#define se second

#define debug(x) cout<<#x<<"="<<x<<endl

using namespace std;

typedef long long LL;

typedef pair<int,int> pii;

int c[][],a[];

char s[];

int main()

{

    freopen("david.in","r",stdin);

    freopen("david.out","w",stdout);

    c[][]=;

    c[][]=;

    c[][]=,c[][]=;

    c[][]=;

    c[][]=,c[][]=;

    c[][]=;

    c[][]=,c[][]=;

    c[][]=,c[][]=,c[][]=;

    int n,i,j;

    cin>>n;

    scanf("%s",s+);

    for(i=;i<=n;i++)

    {

        for(j=;j<=;j++)

            a[j]+=c[s[i]-][j];

    }

    for(j=;j;j--)

        while(a[j])

            printf("%d",j),a[j]--;

    cout<<endl;

    return ;

}

// davidlee1999WTK 2015/

// srO myk Orz

//ios::sync_with_stdio(false);