#define R for(i=0;i<=n;++i)
main(){int n,i;scanf("%d",&n);long a[n+1],b[n+1],sum=0,ans=0;R scanf("%lld",&a[i]);R scanf("%lld",&b[i]);R {sum+=a[i];ans=(ans+sum*b[n-i])%1000000007;}printf("%lld\n",ans);}