program C177
    implicit none
    integer(8) :: N
    integer(8), allocatable, dimension(:) :: A
    integer(8) :: i, ans, b, c, d, c1, c2, j

    read(5,*) N
    allocate(A(N))
    read(5,*) (A(i), i = 1, N)

    

    c = 0
    d = 0
    c1 = 0
    c2 = 0

    do i = 1, N
        c = c + A(i)
        d = d + A(i) * A(i)
        if (c > 1000000007) then
            c1 = c / 1000000007
            c = c - c1 * 1000000007
        end if        
        if (d > 1000000007) then
            c2 = d / 1000000007
            d = d - c2 * 1000000007
        end if
 
    end do

    b = mod(c**2-d,1000000007)

    if (mod(b,2) == 0) then
        ans = b / 2
    else
        ans = (b+1000000007) / 2
    end if





    write(6,*) ans

    
end program C177