Runtime Error
/in/foo.cc: In function 'int DFS(int)': /in/foo.cc:64:1: warning: control reaches end of non-void function [-Wreturn-type] } ^
/in/foo.cc: In function 'int DFS(int)': /in/foo.cc:64:1: warning: control reaches end of non-void function [-Wreturn-type] } ^