/in/foo.cc: In function 'int month(int)':
/in/foo.cc:12:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int tianshu(int, int, int, int)':
/in/foo.cc:27:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^