import static java.lang.Math.*;
import static java.math.BigInteger.*;
import static java.util.Arrays.*;
import static java.util.Collections.*;
import java.math.*;
import java.util.*;
import java.io.*;

public class y774 {
  public static void main(String[] args) { new y774().run(); }
  Scanner in = new Scanner(System.in);
  void _out(Object...os) { System.out.println(deepToString(os)); }
  void _err(Object...os) { System.err.println(deepToString(os)); }

  int N;
  int[] A;
  
  int[] work;
  
  void run() {
    for (; in.hasNext(); ) {
      N = in.nextInt();
      A = new int[N];
      for (int i = 0; i < N; ++i) {
        A[i] = in.nextInt();
      }
      sort(A);
      work = new int[N];
      BigInteger ans = valueOf(-1);
      do {
        if (N >= 2 && (A[N - 1] % 2 == 0 || A[N - 1] % 5 == 0)) {
          continue;
        }
        String str = "";
        for (int i = 0; i < N; ++i) {
          str += Integer.toString(A[i]);
        }
        BigInteger x = new BigInteger(str);
        if (ans.compareTo(x) < 0) {
          if (x.isProbablePrime(100)) {
            ans = x;
          }
        }
      } while (nextPermutation());
      System.out.println(ans);
    }
  }
  
  boolean nextPermutation() {
    for (int i = N - 2; i >= 0; --i) {
      if (A[i] < A[i + 1]) {
        for (int j = N - 1; j > i; --j) {
          if (A[i] < A[j]) {
            int workLen = 0;
            work[workLen++] = A[j];
            for (int k = N - 1; k > j; --k) {
              work[workLen++] = A[k];
            }
            work[workLen++] = A[i];
            for (int k = j - 1; k > i; --k) {
              work[workLen++] = A[k];
            }
            for (int k = i; k < N; ++k) {
              A[k] = work[k - i];
            }
            return true;
          }
        }
      }
    }
    return false;
  }
}