/in/foo.cc: In function 'int main()':
/in/foo.cc:10:23: warning: right operand of comma operator has no effect [-Wunused-value]
  cout<<20-zuoye,yuedu,xingquban;
                       ^~~~~~~~~
/in/foo.cc:10:32: warning: right operand of comma operator has no effect [-Wunused-value]
  cout<<20-zuoye,yuedu,xingquban;
                                ^