typedef long long ll;
#include <bits/stdc++.h>
using namespace std;

const int MAX = 510000;
 const int MOD = 1000000007;
 
 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;
 }
 
  long long modpow(long long a, long long n) {
      long long res = 1;
      while (n > 0) {
          if (n & 1) res = res * a % MOD;
          a = a * a % MOD;
          n >>= 1;
      }
      return res;
  }

int main() {
    COMinit();
    ll a,b,c;
    std::cin >> a>>b>>c;
    ll ans =0;
    for (int i = c-1; i < a+b+c-2; i++) {
        ans += COM(i,c-1)*((modpow(2,i)-1)%MOD*(c-1)%MOD*modpow(i,MOD-2)%MOD+modpow(2,i))%MOD*(COM(a+b-1,b)-COM(i+1-c,b)+MOD)%MOD;
        ans %= MOD;
    }
    std::cout << ans << std::endl;
}