import sequtils,strutils,algorithm,math,sugar,macros,strformat
template get*():string = stdin.readLine().strip()
const INF = 10_0000_0007
let n = get().parseInt()
let A = newSeqWith(n+1,get().parseInt())
let B = newSeqWith(n+1,get().parseInt())
var bSum = B.foldl((a+b) mod INF,0)
var ans = 0
for i,a in A:
  ans = (ans + a * bSum) mod INF
  bSum = (bSum - B[^(1+i)] + INF) mod INF
echo ans