func_code_string: #include <bits/stdc++.h>   using namespace std;   bitset<300000001> b;   int main() {     int l, r, c = 0, i, j;     cin >> l >> r;     for (i = 3; i * i <= r; i += 2)       for (j = i * i; b[i] == 0 and j <= r; j += i) b[j] = 1;     if (l <= 2 and r >= 2) c = 1;     for (i = 5; i <= r; i += 4) c += !b[i] and i >= l;     cout << c;   }   