typedef long long ll; typedef long double ld; #include using namespace std; ll const MOD = 1e9+7; const int MAX = 510000; long long fac[MAX], finv[MAX], inv[MAX]; // テーブルを作る前処理 void COMinit() { fac[0] = fac[1] = 1; finv[0] = finv[1] = 1; inv[1] = 1; for (int i = 2; i < MAX; i++){ fac[i] = fac[i - 1] * i % MOD; inv[i] = MOD - inv[MOD%i] * (MOD / i) % MOD; finv[i] = finv[i - 1] * inv[i] % MOD; } } // 二項係数計算 long long COM(int n, int k){ if (n < k) return 0; if (n < 0 || k < 0) return 0; return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD; } int main() { ll n,m,k; COMinit(); std::cin >> n>>m>>k; ll ans = 0; for (int i = 0; n+m-2*i>=k; i++) { ans += COM(n,i)*COM(m-1,m-i)%MOD*fac[n-1]%MOD*fac[m]%MOD; ans %= MOD; } std::cout << ans << std::endl; }