func_code_string: #include <bits/stdc++.h>   using namespace std;   vector<int> p;   bool first[5000] = {0};   void gen() {     p.push_back(0);     for (int i = 2; i <= 500; i++) {       if (!first[i]) {         p.push_back(i);         for (int j = 2 * i; j <= 500; j += i) {           first[j] = 1;         }       }     }   }   bool isprime(int x) {     int sz = sqrt(x) + 1;     for (int i = 2; i <= sz; i++) {       if (x % i == 0) return 0;     }     return 1;   }   int main() {     gen();     int n;     cin >> n;     if (n <= 500) {       vector<int> ans;       for (int i = 0; i < p.size(); i++) {         if (p[i] > n) break;         for (int j = 0; j <= i; j++) {           for (int k = 0; k <= j; k++) {             if (p[i] + p[j] + p[k] == n) {               if (p[i]) ans.push_back(p[i]);               if (j) ans.push_back(p[j]);               if (k) ans.push_back(p[k]);               cout << ans.size() <<   n ;               for (auto x : ans) {                 cout << x <<    ;               }               return 0;             }           }         }       }     } else {       vector<int> ans;       for (int i = n; i >= n - 500; i--) {         if (isprime(i)) {           ans.push_back(i);           n -= i;           break;         }       }       for (int i = 0; i < p.size(); i++) {         if (p[i] > n) break;         for (int j = 0; j <= i; j++) {           if (p[i] + p[j] == n) {             if (p[i]) ans.push_back(p[i]);             if (p[j]) ans.push_back(p[j]);             cout << ans.size() <<   n ;             for (auto x : ans) {               cout << x <<    ;             }             return 0;           }         }       }     }     return 0;   }   