/* -*- coding: utf-8 -*-
 *
 * 895.cc:  No.895 MESE - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100000;
const int MAX_M = MAX_N * 3;
const int MOD = 1000000007;

/* typedef */

typedef long long ll;

/* global variables */

int fracs[MAX_M + 1], invfs[MAX_M + 1];

/* subroutines */

int powmod(int a, int n) {  // a^n % MOD
  int pm = 1;
  while (n > 0) {
    if (n & 1) pm = (ll)pm * a % MOD;
    a = (ll)a * a % MOD;
    n >>= 1;
  }
  return pm;
}

int invfrac(int n) {
  if (invfs[n] > 0) return invfs[n];
  return (invfs[n] = powmod(fracs[n], MOD - 2));
}

inline ll nck(int n, int k) {  // nCk % MOD
  if (n < 0 || n < k || k < 0) return 0;
  return (ll)fracs[n] * invfrac(n - k) % MOD * invfrac(k) % MOD;
}

/* main */

int main() {
  int a, b, c;
  scanf("%d%d%d", &a, &b, &c);
  int m = a + b + c;

  fracs[0] = invfs[0] = 1;
  for (int i = 1; i <= m; i++)
    fracs[i] = (ll)fracs[i - 1] * i % MOD;

  int sum = 0;
  for (int i = 1; i <= a; i++)
    sum =
      (sum + (ll)nck(m - i - 2, c - 1) * nck(a + b - i - 1, b - 1) % MOD *
       ((powmod(2, m - i - 1) + MOD - 1) % MOD) % MOD) % MOD;

  printf("%d\n", sum);
  return 0;
}