/in/foo.cc: In function 'int main()':
/in/foo.cc:19:30: error: 'z' was not declared in this scope
         else if(year == 9 && z == 30)
                              ^
/in/foo.cc:23:18: error: 'y' was not declared in this scope
         else if((y+z)%2 == 0)
                  ^