/in/foo.cc: In function 'int daysyue(int)':
/in/foo.cc:5:3: error: 'retrun' was not declared in this scope
   retrun 28;
   ^~~~~~
/in/foo.cc: In function 'int daysge(int, int, int, int)':
/in/foo.cc:17:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:19:18: warning: unused variable 'n' [-Wunused-variable]
  int y1,y2,d1,d2,n=0,s1;
                  ^
/in/foo.cc:19:22: warning: unused variable 's1' [-Wunused-variable]
  int y1,y2,d1,d2,n=0,s1;
                      ^~
/in/foo.cc: In function 'int daysyue(int)':
/in/foo.cc:10:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^