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