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>
#include <bits/stdc++.h>
using namespace std;
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
inline long long toll(string s) {
  long long v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T>
inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}
int dcmp(double x, double y) {
  return fabs(x - y) <= 1e-9 ? 0 : x < y ? -1 : 1;
}
int cnt[10];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  string s;
  cin >> s;
  for (int i = 0; i < n; i++) {
    if (s[i] <= '1') {
      continue;
    }
    if (s[i] == '2' || s[i] == '3' || s[i] == '5' || s[i] == '7') {
      cnt[s[i] - '0']++;
    }
    if (s[i] == '4') {
      cnt[2] += 2;
      cnt[3]++;
    }
    if (s[i] == '6') {
      cnt[5]++;
      cnt[3]++;
    }
    if (s[i] == '8') {
      cnt[7]++;
      cnt[2] += 3;
    }
    if (s[i] == '9') {
      cnt[7]++;
      cnt[3] += 2;
      cnt[2]++;
    }
  }
  for (int i = 9; i >= 0; i--) {
    for (int j = 0; j < cnt[i]; j++) {
      cout << i;
    }
  }
  return 0;
}
