#pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #pragma GCC optimize("Ofast") #include #include using namespace std; #if __has_include() #include using namespace atcoder; #endif using ll = long long; using ld = long double; using ull = long long; #define endl "\n" #define REP3(i, m, n) for (int i = (m); (i) < int(n); ++ (i)) #define rep(i,a,b) for(int i=(int)(a);i<(int)(b);i++) #define ALL(x) begin(x), end(x) #define all(s) (s).begin(),(s).end() //#define rep2(i, m, n) for (int i = (m); i < (n); ++i) //#define rep(i, n) rep2(i, 0, n) #define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i) #define drep(i, n) drep2(i, n, 0) #define rever(vec) reverse(vec.begin(), vec.end()) #define sor(vec) sort(vec.begin(), vec.end()) #define fi first #define se second #define pb push_back #define P pair #define REP(i, n) for (int i = 0; i < (n); ++i) #define in scanner.read_int() //const ll mod = 998244353; const ll mod = 1000000007; const ll inf = 4500000000000000000ll; static const long double pi = 3.141592653589793; templatevoid vcin(vector &n){for(int i=0;i>n[i];} templatevoid vcin(vector &n,vector &m){for(int i=0;i>n[i]>>m[i];} templatevoid vcout(vector &n){for(int i=0;ivoid vcin(vector> &n){for(int i=0;i>n[i][j];}}} templatevoid vcout(vector> &n){for(int i=0;iauto min(const T& a){ return *min_element(all(a)); } templateauto max(const T& a){ return *max_element(all(a)); } templatevoid print(pair a){cout<bool chmax(T &a, const T &b) { if (abool chmin(T &a, const T &b) { if (b void ifmin(T t,T u){if(t>u){cout<<-1< void ifmax(T t,T u){if(t>u){cout<<-1<auto make_vector(T x,int arg,Args ...args){if constexpr(sizeof...(args)==0)return vector(arg,x);else return vector(arg,make_vector(x,args...));} ll modPow(ll a, ll n, ll mod) { ll ret = 1; ll p = a % mod; while (n) { if (n & 1) ret = ret * p % mod; p = p * p % mod; n >>= 1; } return ret; } vector divisor(ll x){ vector ans; for(ll i = 1; i * i <= x; i++){ if(x % i == 0) {ans.push_back(i); if(i*i!=x){ ans.push_back(x / ans[i]);}}}sor(ans); return ans; } template struct Sum{ vector data; Sum(const vector& v):data(v.size()+1){ for(ll i=0;i struct Sum2{ vector> data; Sum2(const vector> &v):data(v.size()+1,vector(v[0].size()+1)){ for(int i=0;i buffer; ssize_t n_written; ssize_t n_read; public: Scanner(): buffer(1024*1024) { do_read(); } int64_t read_int() { int64_t ret = 0, sgn = 1; int ch = current_char(); while (isspace(ch)) { ch = next_char(); } if (ch == '-') { sgn = -1; ch = next_char(); } for (; isdigit(ch); ch = next_char()) ret = (ret * 10) + (ch - '0'); return sgn * ret; } private: void do_read() { ssize_t r = read(0, &buffer[0], buffer.size()); if (r < 0) { throw runtime_error(strerror(errno)); } n_written = r; n_read = 0; } inline int next_char() { ++n_read; if (n_read == n_written) { do_read(); } return current_char(); } inline int current_char() { return (n_read == n_written) ? EOF : buffer[n_read]; } }; //Scanner scanner; //void vin(vector &n){for(int i=0;i=n-1&&n-1>=0){ return COM(n+k-1,n-1); } else{ return 0; } } using mint = modint1000000007; int main() { cincout(); ll t; COMinit(); cin>>t; while(t--){ ll a,b; cin>>a>>b; b-=1; mint ans=1; ans*=a; ans*=fac[a+b-2]; ans*=finv[a-1]; ans*=finv[b-1]; ans*=2*a-2; ans/=a; cout<