/in/foo.cc: In function 'int main()':
/in/foo.cc:11:33: error: lvalue required as left operand of assignment
  else if(m==4 ||m==6 ||m==9 ||m=11)
                                 ^~
/in/foo.cc:18:6: error: expected ')' before '{' token
      {
      ^
/in/foo.cc:25:3: error: expected primary-expression before '}' token
   }
   ^
/in/foo.cc:5:13: warning: unused variable 'd' [-Wunused-variable]
     int y,m,d;
             ^