#include #include #include #include #include #include #include #include #include static const int MOD = 1000000007; using ll = long long; using u32 = unsigned; using u64 = unsigned long long; using namespace std; template constexpr T INF = ::numeric_limits::max()/32*15+208; template struct modint{ u32 val; modint(): val(0){} template modint(T t){t %= (T)M; if(t < 0) t += (T)M; val = t;} modint pow(ll k) const { modint res(1), x(val); while(k){ if(k&1) res *= x; x *= x; k >>= 1; } return res; } template modint& operator=(T t){t %= (T)M; if(t < 0) t += (T)M; val = t; return *this;} modint inv() const {return pow(M-2);} modint& operator+=(modint a){val += a.val; if(val >= M) val -= M; return *this;} modint& operator-=(modint a){if(val < a.val) val += M-a.val; else val -= a.val; return *this;} modint& operator*=(modint a){val = (u64)val*a.val%M; return *this;} modint& operator/=(modint a){return (*this) *= a.inv();} modint operator+(modint a) const {return modint(val) +=a;} modint operator-(modint a) const {return modint(val) -=a;} modint operator*(modint a) const {return modint(val) *=a;} modint operator/(modint a) const {return modint(val) /=a;} modint operator-(){return modint(M-val);} bool operator==(const modint a) const {return val == a.val;} bool operator!=(const modint a) const {return val != a.val;} bool operator<(const modint a) const {return val < a.val;} }; using mint = modint; class Factorial { vector facts, factinv; public: explicit Factorial(int n) : facts(n+1), factinv(n+1) { facts[0] = 1; for (int i = 1; i < n+1; ++i) facts[i] = facts[i-1] * mint(i); factinv[n] = facts[n].inv(); for (int i = n-1; i >= 0; --i) factinv[i] = factinv[i+1] * mint(i+1); } mint fact(int k) const { if(k >= 0) return facts[k]; else return factinv[-k]; } mint operator[](const int &k) const { if(k >= 0) return facts[k]; else return factinv[-k]; } mint C(int p, int q) const { if(q < 0 || p < q) return 0; return facts[p] * factinv[q] * factinv[p-q]; } mint P(int p, int q) const { if(q < 0 || p < q) return 0; return facts[p] * factinv[p-q]; } mint H(int p, int q) const { if(p < 0 || q < 0) return 0; return q == 0 ? 1 : C(p+q-1, q); } }; int main() { int n, m, k; cin >> n >> m >> k; Factorial f(n+m); mint ans = 0; for (int i = 2; i <= n+m; ++i) { int l = (i+1)/2, r = i/2; int val = n+m-(i-1+!(i&1)); if(val >= k) ans += f[n-1]*f[m]*f.C(n-1, l-1)*f.C(m-1, r-1) +f[n]*f[m-1]*f.C(m-1, l-1)*f.C(n-1, r-1); } cout << (ans*mint(500000004)).val << "\n"; return 0; }