#include #pragma GCC optimize("Ofast") #define _GLIBCXX_DEBUG using namespace std; using std::cout; using std::cin; using std::endl; using ll=long long; using ld=long double; ll ILL=1167167167167167167; const int INF=2100000000; const ll mod=1e9+7; #define rep(i,a) for (int i=0;i using _pq = priority_queue, greater>; template ll LB(vector &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();} template ll UB(vector &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();} template bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;} template bool chmax(T &a,const T &b){if(a void So(vector &v) {sort(v.begin(),v.end());} template void Sore(vector &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});} void yneos(bool a){if(a) cout<<"YES\n"; else cout<<"NO\n";} namespace po167{ struct combination{ int upper; long long MOD; std::vector fact; std::vector rev; std::vector fact_rev; combination(int max,long long mod):upper(max),MOD(mod),fact(max+1),rev(max+1),fact_rev(max+1){ for(long long i=0;i<=max;i++){ if(i<2){ fact[i]=1; fact_rev[i]=1; rev[i]=1; continue; } fact[i]=(fact[i-1]*i)%mod; rev[i]=mod-((mod/i)*rev[mod%i])%mod; fact_rev[i]=(fact_rev[i-1]*rev[i])%mod; } } long long Comb(int x,int y){ assert(upper>=x); if (x>t; rep(i,t) solve(); } void solve(){ int h,w; cin>>h>>w; if(min(h,w)==1) cout<<"0\n"; else cout<<((ll)(2*(h+w-3))*(table.Comb(h+w-4,h-2)))%mod<<"\n"; }