SUBROUTINE idwt(na,a,nd,d,lf,Lo_D,Hi_D,L,x)
    implicit none
    
    integer :: na,nd,lf,L
    real*8 :: a(na),d(nd),Lo_D(lf),Hi_D(lf),x(L)
    
    real*8 :: temp1(L),temp2(L)
    
    x = 0
    temp1 = 0
    temp2 = 0
    
    call upsconv1(na,a,lf,Lo_D,L,temp1)
    call upsconv1(nd,d,lf,Hi_D,L,temp2)
    
    x = temp1+temp2
    
    end subroutine