#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define llint long long #define inf 1e18 #define rep(x, s, t) for(llint (x) = (s); (x) < (t); (x)++) #define Rep(x, s, t) for(llint (x) = (s); (x) <= (t); (x)++) #define chmin(x, y) (x) = min((x), (y)) #define chmax(x, y) (x) = max((x), (y)) #define mod 1000000007 using namespace std; typedef pair P; const int FACT_MAX = 200005; llint fact[FACT_MAX], fact_inv[FACT_MAX]; llint modpow(llint a, llint n) { if(n == 0) return 1; if(n % 2){ return ((a%mod) * (modpow(a, n-1)%mod)) % mod; } else{ return modpow((a*a)%mod, n/2) % mod; } } void make_fact() { llint val = 1; fact[0] = 1; for(int i = 1; i < FACT_MAX; i++){ val *= i; val %= mod; fact[i] = val; } fact_inv[FACT_MAX-1] = modpow(fact[FACT_MAX-1], mod-2); for(int i = FACT_MAX-2; i >= 0; i--){ fact_inv[i] = fact_inv[i+1] * (i+1) % mod; } } llint comb(llint n, llint k) { llint ret = 1; ret *= fact[n]; ret *= fact_inv[k], ret %= mod; ret *= fact_inv[n-k], ret %= mod; return ret; } llint calc(llint n, llint k) { if(n < k) return 0; return comb(n-k+k-1, k-1); } llint n, m, k; int main(void) { ios::sync_with_stdio(0); cin.tie(0); make_fact(); cin >> n >> m >> k; llint ans = 0; for(int i = 2; i <= n+m-k; i++){ if(i%2 == 0){ ans += calc(n, i/2) * fact[n-1] % mod * calc(m, i/2) % mod * fact[m] % mod; ans %= mod; } else{ ans += calc(n, i-i/2) * fact[n-1] % mod * calc(m, i/2) % mod * fact[m] % mod; ans %= mod; } } cout << ans << endl; return 0; }