func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 100010;   const int M = 55;   const int K = 200010;   const int LIT = 2500;   const int INF = 1 << 30;   const int dir[6][2] = {{2, 0}, {-2, 0}, {1, 1}, {-1, 1}, {1, -1}, {-1, -1}};   bool check(long long x, long long y, long long n) {     long long dist = x * x + 3 * y * y;     long long cmp = 4 * n * n;     return dist <= cmp;   }   bool inside(long long x, long long y, long long n) {     for (int j = 0; j < 6; j++) {       long long xx = x + dir[j][0];       long long yy = y + dir[j][1];       if (!check(xx, yy, n)) return 0;     }     return 1;   }   void solve(int n) {     long long x = 0, y = 0;     long long res = 1;     while (1) {       y += 2;       if (!inside(x, y, n)) break;       res += 2;     }     while (y >= 0) {       x += 3, y++;       while (y >= 0) {         if (inside(x, y, n)) {           res += (y + 1) * 2;           break;         }         y -= 2;       }     }     cout << res << endl;   }   int main() {     int n;     while (cin >> n) {       solve(n);     }   }   