program main
	implicit none
	character :: a*50000,b*100000
	integer nagasa,i
	read(*,*) b
	nagasa=len_trim(b)
	do i=1,(nagasa+1)/2
		a(i:i)=b(2*i-1:2*i-1)
	enddo
	write(*,*)a(1:(nagasa+1)/2)
end program main
