foo.cc: In function 'int main()':
foo.cc:52:6: error: 'gx' was not declared in this scope
  bfs(gx-1,gy-1);
      ^~
foo.cc:52:6: note: suggested alternative: 'hx'
  bfs(gx-1,gy-1);
      ^~
      hx
foo.cc:52:11: error: 'gy' was not declared in this scope
  bfs(gx-1,gy-1);
           ^~
foo.cc:52:11: note: suggested alternative: 'hy'
  bfs(gx-1,gy-1);
           ^~
           hy

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