/in/foo.cc: In function 'int find(int)':
/in/foo.cc:9:7: warning: statement has no effect [-Wunused-value]
  for(r;r!=head[r];r=head[r]);
       ^
/in/foo.cc: In function 'int abs(int)':
/in/foo.cc:6:41: warning: control reaches end of non-void function [-Wreturn-type]
 inline int abs(int a){if(a<0) return -a;}
                                         ^