#include <bits/stdc++.h>   using namespace std;   void display(std::vector<int> v) {     for (int i = 3; i >= 0; i--) {       for (int j = 0; j < v[i]; j++) {         if (i == 3)           cout << 7;         else if (i == 2)           cout << 5;         else if (i == 1)           cout << 3;         else if (i == 0)           cout << 2;       }     }   }   int main() {     int n;     cin >> n;     std::vector<int> v = {0, 0, 0, 0};     while (n--) {       char c;       cin >> c;       if (c ==  2 )         v[0]++;       else if (c ==  3 )         v[1]++;       else if (c ==  4 ) {         v[0] += 2;         v[1]++;       } else if (c ==  5 )         v[2]++;       else if (c ==  6 ) {         v[1] += 1;         v[2]++;       } else if (c ==  7 )         v[3]++;       else if (c ==  8 ) {         v[3]++;         v[0] += 3;       } else if (c ==  9 ) {         v[1] += 2;         v[0]++;         v[3]++;       }     }     display(v);     return 0;   }   