/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author
 */

#include <iostream>
#include <fstream>

#ifndef SOLUTION_COMMON_H

#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using PI = pair<int, int>;
template<class T> using V = vector<T>;
using VI = V<int>;
#define _1 first
#define _2 second

#ifdef MY_DEBUG
# define DEBUG(x) x
#else
# define DEBUG(x)
#endif

template<class T>
inline void debug(T &A) {
  DEBUG(
      for (const auto &a : A) {
        cerr << a << " ";
      }
      cerr << '\n';
  )
}

template<class T, class Func>
inline void debug_with_format(T &A, Func f) {
  DEBUG(
      for (const auto &a : A) {
        cerr << f(a) << " ";
      }
      cerr << '\n';
  )
}

template<class T>
inline void debug_dim2(T &A) {
  DEBUG(
      for (const auto &as : A) {
        debug(as);
      }
  )
}

template<typename ... Args>
inline void debug(const char *format, Args const &... args) {
  DEBUG(
      fprintf(stderr, format, args ...);
      cerr << '\n';
  )
}

template<typename ... Args>
string format(const string &fmt, Args ... args) {
  size_t len = snprintf(nullptr, 0, fmt.c_str(), args ...);
  vector<char> buf(len + 1);
  snprintf(&buf[0], len + 1, fmt.c_str(), args ...);
  return string(&buf[0], &buf[0] + len);
}

template<class T1, class T2>
string fmtP(pair<T1, T2> a) {
  stringstream ss;
  ss << "(" << a._1 << "," << a._2 << ")";
  return ss.str();
}

#define SOLUTION_COMMON_H

#endif //SOLUTION_COMMON_H


class Comb {
public:
  int MOD;
  V<ll> F, I;

  Comb(int N, int MOD): MOD(MOD), F(N + 1), I(N + 1) {
    F[0] = 1;
    for (int i = 1; i <= N; ++i) {
      F[i] = F[i - 1] * i % MOD;
    }

    I[N] = pow_mod(F[N], MOD - 2, MOD);
    for (int i = N - 1; i >= 0; --i) {
      I[i] = I[i + 1] * (i + 1) % MOD;
    }
  }

  static ll pow_mod(ll x, int k, int MOD) {
    ll res = k >= 2 ? pow_mod(x * x % MOD, k / 2, MOD) : 1ll;
    if (k&1) res = res * x % MOD;
    return res;
  };

  ll operator()(int n, int k) {
    if (k < 0 || k > n) return 0ll;
    return F[n] * I[n - k] % MOD * I[k] % MOD;
  };

  ll rev(int x) {
    return F[x - 1] * I[x] % MOD;
  }
};

const int MOD = 1000000007;

class D {
public:
  void solve(std::istream& in, std::ostream& out) {
    int a, b, c;
    in >> a >> b >> c;
    int n = a + b + c;

    // cの、bit毎の現れる回数
    V<ll> cnt(n + 1);
    Comb comb(n, MOD);
    // 先頭のbの左側のaの個数で場合分け
    for (int i = 1; i <= a; ++i) {
      int a1 = a - i;
      int b1 = b - 1;
      int n1 = n - i - 1;
      int bix = n - 1 - i; // 先頭のbの位置
      ll v = comb.F[n1]
          * comb.I[a1] % MOD
          * comb.I[b1] % MOD
          * comb.I[c] % MOD
          * c % MOD
          * comb.rev(bix) % MOD;
      debug("%d %d %d %d %lld", a1, b1, n1, bix, v);
      cnt[0] = (cnt[0] + v) % MOD;
      cnt[bix] = (MOD + cnt[bix] - v) % MOD;
    }
    for (int i = 0; i < n; ++i) {
      cnt[i + 1] = (cnt[i + 1] + cnt[i]) % MOD;
    }
    debug(cnt);
    ll ans = 0ll;
    ll pow2 = 1ll;
    for (int i = 0; i < n; ++i) {
      ans = ans + pow2 * cnt[i] % MOD;
      pow2 = pow2 * 2 % MOD;
    }
    ans %= MOD;
    out << ans;
  }
};


int main() {
	D solver;
	std::istream& in(std::cin);
	std::ostream& out(std::cout);
	solver.solve(in, out);
	return 0;
}