diff --git a/helper.jl b/helper.jl
index c767230..359948d 100644
--- a/helper.jl
+++ b/helper.jl
@@ -1,4 +1,4 @@
-using LinearAlgebra, DelimitedFiles
+using LinearAlgebra, DelimitedFiles, SparseArrays
 
 "Sum over array while minimizing catastrophic cancellation as much as possible"
 function better_sum(arr::Array{T}) where T<:Real