#include using namespace std; #ifdef _DEBUG #include "_DEBUG.hpp" #endif #define int long long const long long inf = 2e18; const int mod = 1e9 + 7; template istream &operator>>(istream &is, vector &v) { for (T &in : v) is >> in; return is; } template vector make_vec(size_t a) { return vector(a); } template auto make_vec(size_t a, Ts... ts) { return vector(ts...))>(a, make_vec(ts...)); } template typename enable_if::value == 0>::type fill(T &t, const V &v) { t = v; } template typename enable_if::value != 0>::type fill(T &t, const V &v) { for (auto &e : t) fill(e, v); } template< int mod > struct ModInt { int x; ModInt() : x(0) {} ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} ModInt &operator+=(const ModInt &p) { if((x += p.x) >= mod) x -= mod; return *this; } ModInt &operator-=(const ModInt &p) { if((x += mod - p.x) >= mod) x -= mod; return *this; } ModInt &operator*=(const ModInt &p) { x = (int) (1LL * x * p.x % mod); return *this; } ModInt &operator/=(const ModInt &p) { *this *= p.inverse(); return *this; } ModInt operator-() const { return ModInt(-x); } ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; } ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; } ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; } ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; } bool operator==(const ModInt &p) const { return x == p.x; } bool operator!=(const ModInt &p) const { return x != p.x; } ModInt inverse() const { int a = x, b = mod, u = 1, v = 0, t; while(b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } return ModInt(u); } ModInt pow(int64_t n) const { ModInt ret(1), mul(x); while(n > 0) { if(n & 1) ret *= mul; mul *= mul; n >>= 1; } return ret; } friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x; } friend istream &operator>>(istream &is, ModInt &a) { int64_t t; is >> t; a = ModInt< mod >(t); return (is); } }; using mint = ModInt< 1000000007 >; struct Combination{ vector fact; // fact[i] = iの階乗 Combination(int n) : fact(n+1){ fact[0] = fact[1] = 1; for(int i = 2; i <= n; i++){ fact[i] = fact[i-1] * i % mod; } } int nCr(int n, int r){ // nCr = n!/r!(n-r)! if(min(n, r) < 0 || n < r) return 0; return fact[n] * inv(fact[r]*fact[n-r]%mod) % mod; } int inv(int n, int p = mod-2){ // a/n ≡ a*n^(p-2) nとpは互いに素 int r = 1; for(; p > 0; p >>= 1){ if(p & 1LL) r = r * n % mod; n = n * n % mod; } return r; // r = n^p % mod } }; signed main() { int t; cin >> t; Combination C(1e6); while (t--) { int h, w; cin >> h >> w; if (min(h, w) == 0) { cout << 0 << endl; continue; } mint ans = 2 * (h + w - 3) * C.nCr(h + w - 4, h - 2); cout << ans << endl; } return 0; }