program main
    implicit none
    integer a, b, c, d
    read(*, *) a, b, c, d
    if(abs(a-c) <= d .or. (abs(a-b) <= d .and. abs(b-c) <= d)) then
        write(*, *) 'Yes'
	else
	    write(*, *) 'No'
	end if
end program main