#include using namespace std; #if __has_include() #include using namespace atcoder; templateistream &operator>>(istream &is,static_modint &a){long long b;is>>b;a=b;return is;} istream &operator>>(istream &is,modint &a){long long b;cin>>b;a=b;return is;} #endif #ifdef LOCAL #include "debug.h" #else #define debug(...) static_cast(0) #define debugg(...) static_cast(0) templateostream &operator<<(ostream &os,const pair&p){os<; templateusing minque=priority_queue,greater>; templatebool chmax(T &a,const T &b){return (abool chmin(T &a,const T &b){return (a>b?(a=b,true):false);} templateistream &operator>>(istream &is,pair&p){is>>p.first>>p.second;return is;} templateistream &operator>>(istream &is,vector &a){for(auto &i:a)is>>i;return is;} templatevoid operator++(pair&a,int n){a.first++,a.second++;} templatevoid operator--(pair&a,int n){a.first--,a.second--;} templatevoid operator++(vector&a,int n){for(auto &i:a)i++;} templatevoid operator--(vector&a,int n){for(auto &i:a)i--;} #define reps(i,a,n) for(int i=(a);i<(n);i++) #define rep(i,n) reps(i,0,n) #define all(x) x.begin(),x.end() #define pcnt(x) __builtin_popcount(x) ll myceil(ll a,ll b){return (a+b-1)/b;} template auto vec(const int (&d)[n],const T &init=T()){ if constexpr (id(d,init)); else return init; } void SOLVE(); int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); #ifdef LOCAL clock_t start=clock(); #endif int testcase=1; //cin>>testcase; for(int i=0;i struct factorial_table{ private: int mod,capacity; vectorfact,factinv,inv; void resize(int n){ fact.resize(n+1),factinv.resize(n+1),inv.resize(n+1); for(int i=capacity+1;i<=n;i++){ fact[i]=fact[i-1]*i; inv[i]=-inv[mod%i]*(mod/i); factinv[i]=factinv[i-1]*inv[i]; } capacity=n; } public: factorial_table():capacity(1),mod(T::mod()),fact{1,1},factinv{1,1},inv{0,1}{} T C(int n,int k){ if(n T O(INT...k){ int n=0; for(int i:initializer_list{k...}){ if(i<0)return 0; n+=i; } if(capacity{k...})ret*=factinv[i]; return ret; } }; using mint=modint1000000007; void SOLVE(){ int n,m,k; cin>>n>>m>>k; factorial_tabletable; mint ans=0; reps(i,1,min(n,m)+1){ if(n-i+m-i>=k){ ans+=table.factorial(n)*table.factorial(m)*table.C(n-1,i-1)*table.C(m-1,i-1)/i; } } cout<