SUBROUTINE detcoef(m,coefs,n,longs,levels,num,d)
    implicit none
    
    integer :: m,n,levels,num
    integer :: longs(n)
    real*8 :: coefs(m),d(1000)
    
    integer :: nmax,tfirst(n),first(n-2),longs2(n-2),last(n-2),i
    
    d = 0
    
    nmax = n-2
    call cumsum(n,longs,tfirst)
    tfirst = tfirst+1
    
    do i=n-2,1,-1
        first(n-i-1) = tfirst(i)
        longs2(n-i-1) = longs(i+1)
    end do
    
    last = first+longs2-1
    
    num = last(levels)-first(levels)+1
    d(1:num) = coefs(first(levels):last(levels))
    
    end subroutine