func_code_string: #include <bits/stdc++.h>   using namespace std;   bool vis[8][8];   int main() {     ios_base::sync_with_stdio(false);     cin.tie(nullptr);     char t;     int y, x;     cin >> t >> y;     --y;     x = t -  a ;     for (int i = 0; i < 8; i++) {       vis[i][y] = true;       vis[x][i] = true;     }     auto mark = [&](int x, int y) {       vis[x][y] = true;       for (int i = -2; i <= 2; i++) {         for (int j = -2; j <= 2; j++) {           if (i * i + j * j != 5) continue;           int dx = x + i, dy = y + j;           if (dx >= 0 && dx < 8 && dy >= 0 && dy < 8) vis[dx][dy] = true;         }       }     };     mark(x, y);     cin >> t >> y;     t;     --y;     mark(t -  a , y);     int cnt = 0;     for (int i = 0; i < 8; i++) {       for (int j = 0; j < 8; j++) cnt += vis[i][j];     }     cout << 64 - cnt;     return 0;   }   