program taka
implicit none
integer:: n,i,j,b,d,count
integer,allocatable,dimension(:):: a
 
read(5,*) n
allocate(a(n))
read(5,*) (a(i),i=1,n)

count=0

 do j=1,n
  do while(d==0)
   b=a(j)/2
   d=a(j)-b*2
    if(d==0)then
     count=count+1
    else
     count=count
    end if
   end do
  end do

write(6,*) count
 
end program taka