implicit none
integer(8) i,N,j,d
integer(8),allocatable :: A(:)
integer(8),allocatable :: B(:)
integer(8),allocatable :: C(:)
read(*,*) N
allocate (A(1:N))
allocate (B(1:N))
allocate (C(1:N))
A=0
B=0
C=0
d=0
read(*,*) (A(i),i=1,N)
do i=1,N
    C(i)=maxval(A)
    A(maxloc(A))=0
end do
do i=1,N-1
    if (C(i)==C(i+1)) then
        B(i)=B(i)-1
        B(i+1)=B(i+1)-1
    end if
end do
do i=1,N
    if (B(i)==0) then
        d=d+1
    end if
end do
write(*,*) d
end