#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; typedef unsigned int ui; const ll mod = 1000000007; const ll INF = (ll)1000000007 * 1000000007; typedef pair P; #define stop char nyaa;cin>>nyaa; #define rep(i,n) for(int i=0;i=0;i--) #define Rep(i,sta,n) for(int i=sta;i=1;i--) #define Rep1(i,sta,n) for(int i=sta;i<=n;i++) typedef long double ld; typedef complex Point; const ld eps = 1e-11; const ld pi = acos(-1.0); typedef pair LP; typedef pair LDP; typedef unsigned long long ul; ll a[1 << 17], b[1 << 17],s[1<<17]; int main() { int n; cin >> n; n++; rep(i, n) { cin >> a[i]; } rep(i, n) { cin >> b[i]; } rep(i, n) { s[i + 1] = s[i] + b[i]; s[i + 1] %= mod; } ll out = 0; rep(i, n) { out += a[i] * s[n - i] % mod; out %= mod; } cout << out << endl; return 0; }