import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

public class Main {

	void run() {
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		String[] a=new String[n];
		ArrayList<String> b=new ArrayList<String>();
		long sum=0;
		for (int i=0;i<n;++i) {
			a[i]=sc.next();
			sum+=Integer.valueOf(a[i]);
		}
		Arrays.sort(a);
		int[] ord=new int[n];
		{
			int p=0;
			for (int i=0;i<n;++i) {
				b.add(a[i]);
				int j=i;
				while (j+1<n && a[i].equals(a[j+1])) {
					++j;
				}
				for (int k=i;k<=j;++k) {
					ord[k]=p;
				}
				i=j;
				++p;
			}
		}
		long ans=-1;
		if (sum%3!=0&&sum%9!=0) {
			do {
				StringBuilder v=new StringBuilder();
				for (int i=0;i<n;++i) v.append(b.get(ord[i]));
				if (ans>Long.valueOf(v.toString())) continue;
				if (new BigInteger(v.toString()).isProbablePrime(10)) ans=Math.max(ans, Long.valueOf(v.toString()));
			} while (nextPermutation(ord));
		}
		System.out.println(ans);
	}
	
	boolean nextPermutation(int[] a) {
		int n=a.length;
		int p=n-1;
		while (p>0 && a[p-1]>=a[p]) --p;
		if (p==0) return false;
		int q=p;
		while (q+1<n && a[p-1]<a[q+1]) ++q;
		a[p-1]^=a[q];a[q]^=a[p-1];a[p-1]^=a[q];
		int s=p,t=n-1;
		while (s<t) {
			a[s]^=a[t];a[t]^=a[s];a[s]^=a[t];
			++s;--t;
		}
		return true;
	}
	
	void tr(Object...objects) {System.out.println(Arrays.deepToString(objects));}
	
	public static void main(String[] args) {
    	new Main().run();
    }
}