#include using namespace std; using lint = long long; template using V = vector; template using VV = V< V >; template struct ModInt { using M = ModInt; unsigned v; constexpr ModInt() : v(0) {} constexpr ModInt(auto x) : v(x >= 0 ? x % P : (P - -x % P) % P) {} constexpr ModInt(unsigned v, int) : v(v) {} static constexpr unsigned p() { return P; } M operator+() const { return *this; } M operator-() const { return {v ? P - v : 0, 0}; } explicit operator bool() const noexcept { return v; } bool operator!() const noexcept { return !(bool)*this; } M operator*(M r) const { return M(*this) *= r; } M operator/(M r) const { return M(*this) /= r; } M operator+(M r) const { return M(*this) += r; } M operator-(M r) const { return M(*this) -= r; } bool operator==(M r) const { return v == r.v; } bool operator!=(M r) const { return !(*this == r); } M& operator*=(M r) { v = (uint64_t)v * r.v % P; return *this; } M& operator/=(M r) { return *this *= r.inv(); } M& operator+=(M r) { if ((v += r.v) >= P) v -= P; return *this; } M& operator-=(M r) { if ((v += P - r.v) >= P) v -= P; return *this; } M inv() const { int a = v, b = P, x = 1, u = 0; while (b) { int q = a / b; swap(a -= q * b, b); swap(x -= q * u, u); } assert(a == 1); return x; } M pow(auto n) const { if (n < 0) return pow(-n).inv(); M res = 1; for (M a = *this; n; a *= a, n >>= 1) if (n & 1) res *= a; return res; } friend M operator*(auto l, M r) { return M(l) *= r; } friend M operator/(auto l, M r) { return M(l) /= r; } friend M operator+(auto l, M r) { return M(l) += r; } friend M operator-(auto l, M r) { return M(l) -= r; } friend ostream& operator<<(ostream& os, M r) { return os << r.v; } friend istream& operator>>(istream& is, M& r) { lint x; is >> x; r = x; return is; } friend bool operator==(auto l, M r) { return M(l) == r; } friend bool operator!=(auto l, M r) { return !(l == r); } }; using Mint = ModInt<(unsigned)1e9 + 7>; V<> factor, mbs; void init(int n) { factor.resize(n + 1, -1); iota(begin(factor) + 2, end(factor), 2); for (int p = 2; p * p <= n; ++p) if (factor[p] == p) { for (int i = p * p; i <= n; i += p) if (factor[i] == i) { factor[i] = p; } } mbs.resize(n + 1); mbs[1] = 1; for (int i = 2; i <= n; ++i) { if (factor[i] == factor[i / factor[i]]) mbs[i] = 0; else mbs[i] = -mbs[i / factor[i]]; } } int main() { cin.tie(nullptr); ios::sync_with_stdio(false); lint h, w; cin >> h >> w; init(min(h, w)); Mint res = h * (w - 1) + w * (h - 1); for (lint d = 1; d < min(h, w); ++d) { lint x = (w - 1) / d, y = (h - 1) / d; res += mbs[d] * 2 * Mint(w * x - d * x * (x + 1) / 2) * Mint(h * y - d * y * (y + 1) / 2); } cout << res << '\n'; }