#include #include #include #include #include #include class strictInput { char *p; off_t cur = 0; off_t len = 0; public: explicit strictInput(int fd = 0) { struct stat st; fstat(fd, &st); p = (char *)mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0); len = st.st_size; } char readChar() { assert(cur != len); return p[cur++]; } void unreadChar() { assert(cur != 0); --cur; } bool isEOF() { return cur == len; } void readEOF() { assert(isEOF()); } void readSpace() { assert(readChar() == ' '); } void readEoln() { assert(readChar() == '\n'); } // reads uint64_t in range [from, to] uint64_t readU64(uint64_t from = 0, uint64_t to = UINT64_MAX) { uint64_t cur = 0; off_t read_cnt = 0; bool leading_zero = false; while (!isEOF()) { char p = readChar(); if (!('0' <= p && p <= '9')) { unreadChar(); break; } uint64_t v = p - '0'; assert(cur <= UINT64_MAX / 10); cur *= 10; assert(cur <= UINT64_MAX - v); cur += v; if (read_cnt == 0 && v == 0) leading_zero = true; ++read_cnt; } if (cur == 0) assert(read_cnt == 1); else assert(!leading_zero); return cur; } // reads int64_t in range [from, to] int64_t readI64(int64_t from = INT64_MIN, int64_t to = INT64_MAX) { uint64_t cur = 0; off_t read_cnt = 0; bool leading_zero = false; bool leading_minus = readChar() == '-'; if (!leading_minus) unreadChar(); while (!isEOF()) { char p = readChar(); if (!('0' <= p && p <= '9')) { unreadChar(); break; } uint64_t v = p - '0'; assert(cur <= UINT64_MAX / 10); cur *= 10; assert(cur <= UINT64_MAX - v); cur += v; if (read_cnt == 0 && v == 0) leading_zero = true; ++read_cnt; } if (cur == 0) assert(read_cnt == 1 && !leading_minus); else assert(!leading_zero); if (cur <= INT64_MAX) { int64_t ret = cur; if (leading_minus) ret = -ret; return ret; } else { assert(leading_minus && cur == uint64_t(INT64_MIN)); return INT64_MIN; } } }; #include #include #include #include #include using namespace std; int main() { strictInput Inp; int N; N = Inp.readI64(1, 100'000); Inp.readEoln(); vector> ev; vector> pts; for (int i = 0; i < N; ++i) { long long a, b; a = Inp.readI64(-1'000'000'000, 1'000'000'000); Inp.readSpace(); b = Inp.readI64(-1'000'000'000, 1'000'000'000); Inp.readEoln(); if (a == 0 && b == 0) continue; ev.emplace_back(-b, a, a, b); ev.emplace_back(b, -a, -a, -b); } Inp.readEOF(); sort(ev.begin(), ev.end(), [&](auto a, auto b) { auto [ax, ay, a1, a2] = a; auto [bx, by, b1, b2] = b; bool ar = make_pair(ax, ay) > make_pair(0LL, 0LL); bool br = make_pair(bx, by) > make_pair(0LL, 0LL); if(ar!=br) return br; return ax*by > bx*ay; }); long long x = 0, y = 0; for (auto [xe, ye, v1, v2] : ev) { x += v1; y += v2; pts.emplace_back(x, y); } const int MOD = 1e9 + 7; long long A = 0, B = 0; for (int i = 0; i < (int)pts.size(); ++i) { int j = (i + 1) % (int)pts.size(); auto [ax, ay] = pts[i]; auto [bx, by] = pts[j]; A = (A + ((ax % MOD) * (by % MOD)) - ((bx % MOD) * (ay % MOD))) % MOD; B = (B + gcd(abs(ax - bx), abs(ay - by))) % MOD; } if (A < 0) A += MOD; if (A % 2 == 1) A += MOD; A /= 2; long long hB = B; if (hB < 0) hB += MOD; if (hB % 2 == 1) hB += MOD; hB /= 2; long long ans = (A + hB + 1) % MOD; cout << ans << endl; }