func main()
	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]
		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 :% 10 ^ 9 + 7
	end for
	do cui@print("\{ans}\n")
end func