func main() const mod: int :: 1000000007 var ss: [][]char var n: int :: cui@input().toInt(&) + 1 var a: []int :: #[n]int for i(0, n - 1) do a[i] :: cui@input().toInt(&) if(i <> 0) do a[i] :+ a[i - 1] do a[i] :% mod end if end for var b: []int :: #[n]int for i(0, n - 1) do b[i] :: cui@input().toInt(&) end for var ans: int :: 0 for i(0, n - 1) do ans :+ a[i] * b[n - 1 - i] do ans :% mod end for do cui@print("\{ans}\n") end func