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 LL = long long;
int n;
char str[16];
std::vector<int> answer;
int count[4];
void solve(int l, int r) {
  for (int i = l; i <= r; ++i) {
    for (int j = 2; j <= 3; ++j) {
      int t = i;
      while (t % j == 0) {
        count[j]++;
        t /= j;
      }
    }
  }
}
void work() {
  for (int i = 0; i < n; ++i) {
    if (str[i] == '0' || str[i] == '1') continue;
    int d = str[i] - '0';
    if (d == 2) {
      solve(2, 2);
    } else if (d == 3) {
      solve(2, 3);
    } else if (d == 4) {
      solve(2, 4);
    } else if (d == 5) {
      answer.push_back(5);
    } else if (d == 6) {
      answer.push_back(5);
      solve(6, 6);
    } else if (d == 7) {
      answer.push_back(7);
    } else if (d == 8) {
      answer.push_back(7);
      solve(8, 8);
    } else if (d == 9) {
      answer.push_back(7);
      solve(8, 9);
    }
  }
  if (count[2] < count[3])
    while (true)
      ;
  for (int i = 0; i < count[3]; ++i) {
    answer.push_back(3);
  }
  for (int i = 0; i < count[2] - count[3]; ++i) {
    answer.push_back(2);
  }
  std::sort(answer.begin(), answer.end(), std::greater<int>());
  for (auto t : answer) {
    printf("%d", t);
  }
  puts("");
}
int main() {
  scanf("%d", &n);
  scanf("%s", str);
  work();
  return 0;
}
