implicit none
integer(8) A,i
character(10) S,T
character(10),allocatable :: X(:),Y(:)
read(*,*) S
allocate (X(9))
allocate (Y(9))
T="yukicoder"
do i=1,9
   X(i)=S(i:i)
   Y(i)=T(i:i)
   if (X(i)/=Y(i)) then
       write(*,*) Y(i:i)
       exit
   end if
end do
end