func_code_string: #include <bits/stdc++.h>   using namespace std;   bool isprime(int n) {     if (n < 2) return false;     for (int i = 2; i * i <= n; i++)       if (n % i == 0) return false;     return true;   }   int main() {     int n;     cin >> n;     if (isprime(n))       cout <<  1  << endl;     else if (n % 2 == 0)       cout <<  2  << endl;     else if (isprime(n - 2))       cout <<  2  << endl;     else       cout <<  3  << endl;     return 0;   }   