program main
    use,intrinsic :: iso_fortran_env
    implicit none
    integer(int32):: n,m,i,a,b
    integer(int32), allocatable:: e(:)
    logical:: yes

    read*, n,m
    allocate(e(n), source=0)
    do i=1, m
        read*, a,b
        e(a)=e(a)+1; e(b)=e(b)+1
    end do

    yes = .true.

    do i=1,n
        yes = yes .and. mod(e(i),2) == 0
    end do

    if (yes) then
        print'(a)', 'YES'
    else
        print'(a)', 'NO'
    end if
end program main