#include #include #include #include #include #include #include #include #include #include #include #include #define pb push_back #define rep(i, n) for (int i = 0; i < (n); i++) #define reps(i, n, s) for (int i = (s); i < (n); i++) #define rrep(i, n) for (int i = (n - 1); i >= 0; i--) #define rreps(i, n, s) for (int i = s; i >= n; i--) using ll = long long; using namespace std; constexpr long long MAX = 5100000; constexpr long long INF = 1LL << 60; constexpr int MOD = 1000000007; class mint { public: long long x; mint(long long x = 0) : x((x % MOD + MOD) % MOD) {} mint operator-() const { return mint(-x); } mint& operator+=(const mint& a) { if ((x += a.x) >= MOD) x -= MOD; return *this; } mint& operator-=(const mint& a) { if ((x += MOD - a.x) >= MOD) x -= MOD; return *this; } mint& operator*=(const mint& a) { (x *= a.x) %= MOD; return *this; } mint operator+(const mint& a) const { mint res(*this); return res += a; } mint operator-(const mint& a) const { mint res(*this); return res -= a; } mint operator*(const mint& a) const { mint res(*this); return res *= a; } mint pow(ll t) const { if (!t) return 1; mint a = pow(t >> 1); a *= a; if (t & 1) a *= *this; return a; } // for prime MOD mint inv() const { return pow(MOD - 2); } mint& operator/=(const mint& a) { return (*this) *= a.inv(); } mint operator/(const mint& a) const { mint res(*this); return res /= a; } friend ostream& operator<<(ostream& os, const mint& m) { os << m.x; return os; } }; int main() { cin.tie(0); ios::sync_with_stdio(false); mint a, b; ll _a, _b; cin >> _a >> _b; a = _a, b = _b; if ((_a % 2) == (_b % 2)) { mint res = (mint)2 * a * b + a + b + 1LL; cout << res << endl; } else { mint res = (mint)2 * a * b + a + b; cout << res << endl; } return 0; }