program yuki3039
    integer N, H
    integer A(10**6), B(10**6)
    
    integer i, j
    integer :: max_num = 0
    integer temp
    
    read *, N, H
    
    do i = 1, N
        read *, A(i), B(i)
    end do
    
    do i = 1, H
        temp = 0
        do j = 1, N
            if (A(j) <= i .and. i < B(j)) then
                temp = temp + 1
            end if
        end do
        
        if (temp > max_num) then
            max_num = temp
        end if
    end do
    
    print *, max_num
end program yuki3039