#pragma region include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; #define dump(x) cerr << #x << " = " << (x) << " [" << __LINE__ << ":" << __FUNCTION__ << "] " << endl // vector???��?��??��?��o???��?��??��?��???��?��??��?�� template < typename T > ostream& operator<<(ostream& os, vector< T >& v) { os << "{"; for (int i = 0; i < (int)v.size(); i++) { os << v[i] << (i < v.size() - 1 ? ", " : ""); } os << "}"; return os; } // pair???��?��??��?��o???��?��??��?��???��?��??��?�� template < typename T, typename U > ostream& operator<<(ostream& os, const pair< T, U >& p) { return os << "(" << p.first << ", " << p.second << ")"; } // map???��?��??��?��o???��?��??��?��???��?��??��?�� template < typename T, typename U > ostream& operator<<(ostream& os, const map< T, U >& map_var) { os << "{"; for (auto itr = map_var.begin(); itr != map_var.end(); itr++) { os << "(" << itr->first << ", " << itr->second << ")"; itr++; if (itr != map_var.end()) os << ", "; itr--; } os << "}"; return os; } // set ???��?��??��?��o???��?��??��?��???��?��??��?�� template < typename T > ostream& operator<<(ostream& os, const set< T >& set_var) { os << "{"; for (auto itr = set_var.begin(); itr != set_var.end(); itr++) { os << *itr; ++itr; if (itr != set_var.end()) os << ", "; itr--; } os << "}"; return os; } // multiset ???��?��??��?��o???��?��??��?��???��?��??��?�� template < typename T > ostream& operator<<(ostream& os, const multiset< T >& set_var) { os << "{"; for (auto itr = set_var.begin(); itr != set_var.end(); itr++) { os << *itr; ++itr; if (itr != set_var.end()) os << ", "; itr--; } os << "}"; return os; } #pragma endregion ///////////////////////////////////////// template< int MOD > struct mint { public: unsigned int x; mint() : x(0) {} mint(long long v) { long long w = (long long)(v % (long long)(MOD)); if (w < 0) w += MOD; x = (unsigned int)(w); } mint(std::string &s) { unsigned int z = 0; for (int i = 0; i < s.size(); i++) { z *= 10; z += s[i] - '0'; z %= MOD; } x = z; } mint operator+() const { return *this; } mint operator-() const { return mint() - *this; } mint& operator+=(const mint &a) { if ((x += a.x) >= MOD) x -= MOD; return *this; } mint& operator-=(const mint &a) { if ((x -= a.x) >= MOD) x += MOD; return *this; } mint& operator*=(const mint &a) { unsigned long long z = x; z *= a.x; x = (unsigned int)(z % MOD); return *this; } mint& operator/=(const mint &a) {return *this = *this * a.inv(); } friend mint operator+(const mint& lhs, const mint& rhs) { return mint(lhs) += rhs; } friend mint operator-(const mint& lhs, const mint& rhs) { return mint(lhs) -= rhs; } friend mint operator*(const mint& lhs, const mint& rhs) { return mint(lhs) *= rhs; } friend mint operator/(const mint& lhs, const mint& rhs) { return mint(lhs) /= rhs; } friend bool operator==(const mint& lhs, const mint& rhs) { return lhs.x == rhs.x; } friend bool operator!=(const mint& lhs, const mint& rhs) { return lhs.x != rhs.x; } friend std::ostream& operator<<(std::ostream &os, const mint &n) { return os << n.x; } friend std::istream &operator>>(std::istream &is, mint &n) { unsigned int x; is >> x; n = mint(x); return is; } mint inv() const { assert(x); return pow(MOD-2); } mint pow(long long n) const { assert(0 <= n); mint p = *this, r = 1; while (n) { if (n & 1) r *= p; p *= p; n >>= 1; } return r; } // 存在しない場合0を返す(二乗して確認). // O(log^2MOD) mint sqrt() const { if (this->x < 2) return *this; if (this->pow((MOD-1)>>1).x != 1) return mint(0); mint b = 1, one = 1; while (b.pow((MOD-1) >> 1) == 1) b += one; long long m = MOD-1, e = 0; while (m % 2 == 0) m >>= 1, e += 1; mint x = this->pow((m - 1) >> 1); mint y = (*this) * x * x; x *= (*this); mint z = b.pow(m); while (y.x != 1) { int j = 0; mint t = y; while (t != one) j += 1, t *= t; z = z.pow(1LL << (e-j-1)); x *= z; z *= z; y *= z; e = j; } return x; } }; constexpr int MOD = 1e9 + 7; using coord_t = ll; struct Point { coord_t x,y; Point():x(0),y(0){} Point(coord_t x, coord_t y):x(x),y(y){} bool operator<(const Point &p) const { return x < p.x || (x == p.x && y < p.y); } friend std::ostream &operator<<(std::ostream &os, const Point &v) { return os << "[" << v.x << "," << v.y << "]"; } }; struct Vector { private: // https://codeforces.com/blog/entry/72815?#comment-570942 inline int quad(coord_t x, coord_t y) const { return ((x>=0)^(y>=0))|((y>=0)<<1); } public: coord_t x,y; Vector():x(0),y(0){} Vector(coord_t x, coord_t y):x(x),y(y){} Vector(const Vector &v):x(v.x),y(v.y){} Vector operator-() const { return Vector() - *this; } Vector& operator+=(const Vector &v) { x += v.x; y += v.y; return *this; } Vector& operator-=(const Vector &v) { x -= v.x; y -= v.y; return *this; } friend Vector operator+(const Vector& lv, const Vector& rv) { return Vector(lv) += rv; } friend Vector operator-(const Vector& lv, const Vector& rv) { return Vector(lv) -= rv; } // (-pi,pi] bool operator<(const Vector &v) const { return quad(x,y)==quad(v.x,v.y)?x*v.y>y*v.x:quad(x,y) area(const vector &p) { int n = p.size(); if (n <= 2) return 0; mint ans = 0; for (int i = 0; i < n; i++) { ans += cross(p[i],p[(i+1)%n]); } return ans; } // 多角形内の格子点の数え上げ // (内部,辺上) pair,mint> picks_theorem(const vector &p) { int n = p.size(); mint b = 0; for (int i = 0; i < n; i++) { coord_t dx = abs(p[(i+1)%n].x-p[i].x); coord_t dy = abs(p[(i+1)%n].y-p[i].y); b += __gcd(dx,dy); } return {(area(p)-b+2)/2,b}; } int main() { int n;cin >> n; vector vec(2*n); for (int i = 0; i < n; i++) { cin >> vec[2*i].x >> vec[2*i].y; vec[2*i+1].x = -vec[2*i].x; vec[2*i+1].y = -vec[2*i].y; } sort(vec.begin(), vec.end()); vector a; Vector now(0,0); for (int i = 0; i < 2*n; i++) { a.push_back(Point(now.x,now.y)); now += vec[i]; } auto ans = picks_theorem(a); cout << ans.first + ans.second << endl; return 0; } /////////////////////////////////////////