func_code_string: #include <bits/stdc++.h>   int main() {     int n, amount(0);     scanf( %d , &n);     bool b[3001] = {false};     int pfactors[3001] = {0};     for (int i = 2; i <= n; ++i) {       if (!b[i]) {         for (int j = i + i; j <= n; j += i) {           b[j] = true;           pfactors[j] += 1;         }       }       if (pfactors[i] == 2) {         amount += 1;       }     }     printf( %d n , amount);     return 0;   }   