/in/foo.cc: In function 'int bfs_dist(int, int, int, int, const std::set<std::pair<int, int> >&)':
/in/foo.cc:55:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17' [-Wc++17-extensions]
   55 |         auto [x, y] = q.front(); q.pop();
      |              ^
/in/foo.cc: In function 'int solve(State)':
/in/foo.cc:140:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17' [-Wc++17-extensions]
  140 |         auto [s, step] = Q.front(); Q.pop();
      |              ^