/in/foo.cc: In function 'int main()':
/in/foo.cc:65:17: warning: 'd' may be used uninitialized in this function [-Wmaybe-uninitialized]
   DFS(0,1,T,c,d);
                 ^
/in/foo.cc:65:17: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
/in/foo.cc:60:17: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
   DFS(0,0,S,a,b);
                 ^
/in/foo.cc:60:17: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]