#include using namespace std; using lint = long long int; using pint = pair; using plint = pair; struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_; #define ALL(x) (x).begin(), (x).end() #define SZ(x) ((lint)(x).size()) #define POW2(n) (1LL << (n)) #define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i=i##_begin_;i--) #define REP(i, n) FOR(i,0,n) #define IREP(i, n) IFOR(i,0,n) template void ndarray(vector &vec, int len) { vec.resize(len); } template void ndarray(vector &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) ndarray(v, args...); } template bool mmax(T &m, const T q) { if (m < q) {m = q; return true;} else return false; } template bool mmin(T &m, const T q) { if (m > q) {m = q; return true;} else return false; } template pair operator+(const pair &l, const pair &r) { return make_pair(l.first + r.first, l.second + r.second); } template pair operator-(const pair &l, const pair &r) { return make_pair(l.first - r.first, l.second - r.second); } template istream &operator>>(istream &is, vector &vec){ for (auto &v : vec) is >> v; return is; } ///// This part below is only for debug, not used ///// template ostream &operator<<(ostream &os, const vector &vec){ os << "["; for (auto v : vec) os << v << ","; os << "]"; return os; } template ostream &operator<<(ostream &os, const deque &vec){ os << "deq["; for (auto v : vec) os << v << ","; os << "]"; return os; } template ostream &operator<<(ostream &os, const set &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const unordered_set &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const multiset &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const unordered_multiset &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const pair &pa){ os << "(" << pa.first << "," << pa.second << ")"; return os; } template ostream &operator<<(ostream &os, const map &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const unordered_map &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; } #define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl; ///// END ///// constexpr lint MOD = 1000000007; void fast_integer_zeta(vector &f) { int N = f.size() - 1; vector is_prime(N + 1, 1); for (int p = 2; p <= N; p++) if (is_prime[p]) { for (int q = p * 2; q <= N; q += p) is_prime[q] = 0; for (int j = N / p * p; j > 0; j -= p) (f[j / p] += f[j]) %= MOD; } } void fast_integer_moebius(vector &f) { int N = f.size() - 1; vector is_prime(N + 1, 1); for (int p = 2; p <= N; p++) if (is_prime[p]) { for (int q = p * 2; q <= N; q += p) is_prime[q] = 0; for (int j = p; j <= N; j += p) (f[j / p] += MOD - f[j]) %= MOD; } } int main() { lint H, W; cin >> H >> W; vector vh(max(H, W)), vw(max(H, W)); REP(i, H) vh[i] = (H - i); REP(i, W) vw[i] = (W - i); fast_integer_zeta(vh); fast_integer_zeta(vw); REP(i, vh.size()) vh[i] = vh[i] * vw[i] % MOD; fast_integer_moebius(vh); cout << (vh[1] * 2 + H * (W - 1) + (H - 1) * W) % MOD << endl; }