// see https://gist.github.com/LumaKernel/ff55d49ee1af69b7388f15b707e75c15
const bool DEBUG = 1;
#include <iostream>
#include <vector>
#include <array>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <stack>
#include <tuple>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <complex>
#include <random>
#include <iomanip>
#include <cassert>
#include <functional>

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using  P = tuple<ll, ll>;
using  P3 = tuple<ll, ll, ll>;
using  VI = vector<int>;
using  VL = vector<ll>;
using  VP = vector<P>;
using  VS = vector<string>;

#define omajinai ios::sync_with_stdio(false);cin.tie(0)

#define FOR(i,a,b) for(int i=int(a);i<int(b);++i)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,a,b) for(int i=int(b)-1;i>=int(a);--i)
#define RREP(i,n) RFOR(i,0,n)

#define ALL(a) (a).begin(),(a).end()
#define UNIQUE(a) (a).erase(unique(ALL(a)),(a).end())
#define PB push_back
#define EACH(i,c) REP(i,(c).size())
#define REACH(i,c) RREP(i,(c).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort(ALL(c))

#define BR cout<<"\n"

#define dump(x) if(DEBUG) cerr<<"["<<__LINE__<< "] "<<#x<<"="<<(x)<<"\n"
#define dump2(x,y) if(DEBUG) cerr<<"["<<__LINE__<< "] "<<#x<<"="<<(x)\
  <<" , "<<#y<<"="<<(y)<<"\n"
#define dump3(x,y,z) if(DEBUG)cerr<<"["<<__LINE__<<"] "<<#x<<"="<<(x)\
  <<" , "<<#y<<"="<<(y)\
  <<" , "<<#z<<"="<<(z)<<"\n"

#define SAY(x) if(DEBUG) cerr<<"["<<__LINE__<< "] "<<(x)<<"\n"

#define YES(x) cout<<((x)?"YES":"NO")<<"\n"
#define Yes(x) cout<<((x)?"Yes":"No")<<"\n"
#define yes(x) cout<<((x)?"yes":"no")<<"\n"

inline int omajinai_int_in(){omajinai;int n;cin>>n;return n;}
inline ll omajinai_ll_in(){omajinai;ll n;cin>>n;return n;}
inline string omajinai_string_in(){omajinai;string n;cin>>n;return n;}
inline int int_in(){int n;cin>>n;return n;}
inline ll ll_in(){ll n;cin>>n;return n;}
inline string string_in(){string n;cin>>n;return n;}
#define oini omajinai_int_in()
#define oinl omajinai_ll_in()
#define oins omajinai_string_in()
#define ini int_in()
#define inl ll_in()
#define ins string_in()

#define isInside(y,x) (0<=(y)&&(y)<h&&0<=(x)&&(x)<w)

#define fi(x) (get<0>(x))
#define se(x) (get<1>(x))
#define th(x) (get<2>(x))
#define fo(x) (get<3>(x))

template <typename T> ostream &operator<<(ostream &o, const vector<T> &v) { o << '['; EACH(i, v) o << v[i] << (i != v.size()-1 ? ", " : ""); o << "]";  return o; }

constexpr int INF = 1e9+1;
constexpr ll LINF = 1e18+1;
constexpr int MOD = 1e9+7; template <typename T> function<T(T,T)> constexpr mmin(){ return [](T x, T y){return x<y?x:y;}; }
template <typename T> function<T(T,T)> constexpr mmax(){ return [](T x, T y){return x>y?x:y;}; }
template <typename T> function<T(T,T)> constexpr madd(){ return [](T x, T y){return x+y;}; }
template <typename T> function<T(T,T)> constexpr modadd(){ return [](T x, T y){return ((x+y)%MOD+MOD)%MOD;}; }

ll ans;
const int N = 1e6;

ll pascalsum[N];

int add(int a, int b) {
	return ((((ll) a + b) % MOD) + MOD) % MOD;
}

int mul(int a, int b){
	return (ll)a*b%MOD;
}

int pow(int a, int b) {
	int res = 1;
	while(b) {
		if(b&1) res = mul(res, a);
		a = mul(a, a);
		b >>=1;
	}
	return res;
}

int inv(int a) {
	return pow(a, MOD - 2);
}

int fact[N];
int invFact[N];

int nCr(int n, int r) {
	return mul(fact[n], mul(invFact[r], invFact[n-r]));
}

int main() {
	//#####//
	fact[0]  = invFact[0] = 1;
	FOR(i, 1, N) {
		fact[i] = (ll)fact[i-1] * i % MOD;
		invFact[i] = inv(fact[i]);
	}

	int n=ini, M=ini, K=ini;
	pascalsum[0] = 1;
	FOR(i, 1, M + K + 1) {
		pascalsum[i] = mul(2, pascalsum[i-1]);
		if(i >= M + 1) pascalsum[i] = add(pascalsum[i], - nCr(i-1, M));
		if(i >= K + 1) pascalsum[i] = add(pascalsum[i], - nCr(i-1, i - (K + 1)));
	}

	FOR(t, n, n+M+K+1) {
		int T = n + M + K;
		ans += ((ll)(nCr(t-1, n-1)) * pow(3, T-t) % MOD) * pascalsum[t-n] % MOD; ///
		ans %= MOD;
	}
	cout << ans << endl;
}

//


Measured memory_bytes: 14592