#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<iomanip>
#include<math.h>
#include<complex>
#include<queue>
#include<deque>
#include<stack>
#include<map>
#include<set>
#include<bitset>
#include<functional>
#include<assert.h>
#include<numeric>
using namespace std;
#define REP(i,m,n) for(int i=(int)(m) ; i < (int) (n) ; ++i )
#define rep(i,n) REP(i,0,n)
using ll = long long;
const int inf=1e9+7;
const ll longinf=1LL<<60 ;
const ll mod=1e9+7 ;


vector<ll> inv,fact,invfact;
void mod_build(int n=101010){
	fact.resize(n+1);
	inv.resize(n+1);
	invfact.resize(n+1);
	fact[0]=inv[0]=invfact[0]=1;
	inv[1]=1;
	rep(i,n){
		fact[i+1]=fact[i]*(i+1)%mod;
		if(i>0)inv[i+1]=mod-inv[mod%(i+1)]*(mod/(i+1))%mod;
		invfact[i+1]=invfact[i]*inv[i+1]%mod;
	}
}
ll perm(int n,int k){
	if(n<0||k<0||k>n)return 0;
	return fact[n]*invfact[n-k]%mod;
}
ll comb(int n,int k){
	if(n<0||k<0||k>n)return 0;
	return (fact[n]*invfact[n-k]%mod)*invfact[k]%mod;
}
ll powmod(ll n,ll k){
	k%=mod-1;
	if(k<0)k+=mod-1;
	ll ret=1;
	while(k){
		if(k&1)ret=ret*n%mod;
		n=n*n%mod;
		k>>=1;
	}
	return ret;
}
int main(){
	int x,y,z;
	cin>>x>>y>>z;
	mod_build(3234567);
	vector<ll> calc(x+y+z+1);
	vector<ll> sum(x+y+z+1);
	ll ans =0;
	sum[0]=1;
	int n = x+y+z;
	rep(i,n){
		sum[i+1]=3*mod+comb(n+1,i+1)-2*sum[i];
		sum[i+1]%=mod;
	}
	REP(i,1,x+y+z+1){
		ll ret = comb(x+i-1,x)*comb(y+i-1,y)%mod*comb(z+i-1,z)%mod;
		if((n-i)%2==0)ans+=ret*sum[n-i]%mod;
		else ans+=mod-ret*sum[n-i]%mod;
		ans%=mod;
	}
	//rep(i,x+y+z+1)cout<<calc[i]<<" ";
	cout<<ans%mod<<endl;
	return 0;
}