#define _CRT_SECURE_NO_WARNINGS #include "bits/stdc++.h" //#include "libs.h" #include #include #include //#include //#include //#include using namespace std; //呪文 #define DUMPOUT cerr #define dump(...) DUMPOUT<<" ";DUMPOUT<<#__VA_ARGS__<<" :["<<__LINE__<<":"<<__FUNCTION__<<"]"< pii; typedef pair pll; typedef pair pdd; typedef pair pss; template ostream& operator << (ostream& o, const pair<_KTy, _Ty>& m) { o << "{" << m.first << ", " << m.second << "}"; return o; } template ostream& operator << (ostream& o, const map<_KTy, _Ty>& m) { if (m.empty()) { o << "{ }"; return o; } o << "{" << *m.begin(); for (auto itr = ++m.begin(); itr != m.end(); itr++) { o << ", " << *itr; } o << "}"; return o; } template ostream& operator << (ostream& o, const unordered_map<_KTy, _Ty>& m) { if (m.empty()) { o << "{ }"; return o; } o << "{" << *m.begin(); for (auto itr = ++m.begin(); itr != m.end(); itr++) { o << ", " << *itr; } o << "}"; return o; } template ostream& operator << (ostream& o, const vector<_Ty>& v) { if (v.empty()) { o << "{ }"; return o; } o << "{" << v.front(); for (auto itr = ++v.begin(); itr != v.end(); itr++) { o << ", " << *itr; } o << "}"; return o; } template ostream& operator << (ostream& o, const set<_Ty>& s) { if (s.empty()) { o << "{ }"; return o; } o << "{" << *(s.begin()); for (auto itr = ++s.begin(); itr != s.end(); itr++) { o << ", " << *itr; } o << "}"; return o; } template ostream& operator << (ostream& o, const unordered_set<_Ty>& s) { if (s.empty()) { o << "{ }"; return o; } o << "{" << *(s.begin()); for (auto itr = ++s.begin(); itr != s.end(); itr++) { o << ", " << *itr; } o << "}"; return o; } template ostream& operator << (ostream& o, const stack<_Ty>& s) { if (s.empty()) { o << "{ }"; return o; } stack<_Ty> t(s); o << "{" << t.top(); t.pop(); while (!t.empty()) { o << ", " << t.top(); t.pop(); } o << "}"; return o; } template ostream& operator << (ostream& o, const list<_Ty>& l) { if (l.empty()) { o << "{ }"; return o; } o << "{" << l.front(); for (auto itr = ++l.begin(); itr != l.end(); ++itr) { o << ", " << *itr; } o << "}"; return o; } template istream& operator >> (istream& is, pair<_KTy, _Ty>& m) { is >> m.first >> m.second; return is; } template istream& operator >> (istream& is, vector<_Ty>& v) { for (size_t i = 0; i < v.size(); i++) is >> v[i]; return is; } namespace aux { // print tuple template struct tp { static void print(ostream& os, const Ty& v) { os << get(v) << ", "; tp::print(os, v); } }; template struct tp { static void print(ostream& os, const Ty& v) { os << get(v); } }; } template ostream& operator<<(ostream& os, const tuple& t) { os << "{"; aux::tp, 0, sizeof...(Tys) - 1>::print(os, t); os << "}"; return os; } template inline void Fill(A(&array)[N], const T &val) { std::fill((T*)array, (T*)(array + N), val); } void dump_func() { DUMPOUT << endl; } template void dump_func(Head&& head, Tail&&... tail) { DUMPOUT << head; if (sizeof...(Tail) == 0) { DUMPOUT << " "; } else { DUMPOUT << ", "; } dump_func(std::move(tail)...); } #define PI 3.14159265358979323846 #define EPS 1e-10 #define FOR(i,a,n) for(int i=(a);i<(n);++i) #define REP(i,n) FOR(i,0,n) #define all(j) (j).begin(), (j).end() #define SZ(j) ((int)(j).size()) #define fake false int main() { cin.tie(0); ios::sync_with_stdio(false); const ll MOD = 1000000007; int n; cin >> n; vector a(n + 1), b(n + 1), sb(n + 1, 0); cin >> a >> b; sb[0] = b[0]; for (int i = 1; i <= n; i++) sb[i] = (sb[i - 1] + b[i]) % MOD; ll ans = 0; for (int i = 0; i <= n; i++) { ans += a[i] * sb[n - i]; ans %= MOD; } cout << ans << endl; return 0; }