func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 3e8;   int l, r, cnt, ans1, pre1[20000005];   bitset<maxn> pre;   int max1, max2;   int main() {     cin >> l >> r;     pre[1] = pre[0] = 1;     ans1 = 1;     for (int yui = 2; yui <= r; yui++) {       if (pre[yui] == 0) {         cnt++;         pre1[cnt] = yui;         if (yui % 4 == 1) ans1++;       }       if (yui == l - 1) max1 = ans1;       if (yui == r) max2 = ans1;       for (int j = 1; j <= cnt && pre1[j] * yui <= r; j++) {         pre[yui * pre1[j]] = 1;         if (yui % pre1[j] == 0) break;       }     }     cout << max2 - max1;   }   