/in/foo.cc: In function 'int dfs(int, int, int)':
/in/foo.cc:66:1: warning: no return statement in function returning non-void [-Wreturn-type]
   66 | }
      | ^
/in/foo.cc:53:5: warning: infinite recursion detected [-Winfinite-recursion]
   53 | int dfs(int x,int dep,int root)
      |     ^~~
/in/foo.cc:63:16: note: recursive call
   63 |             dfs(to[i],dep+1,root);
      |             ~~~^~~~~~~~~~~~~~~~~~