#include<bits/stdc++.h>
using namespace std;
#ifdef DEBUG
#include"debug.h"
#else
#define debug(...) void()
#endif
#define all(x) (x).begin(),(x).end()
template<class T>
auto ary(T *a,int l,int r){
	return vector<T>{a+l,a+1+r};
}
using ll=long long;
using ull=unsigned ll;
const int N=3e4+10,mod=998244353;
ll qpow(ll x,ll y=mod-2,ll ans=1){
	for(;y;(x*=x)%=mod,y>>=1)if(y&1)(ans*=x)%=mod;
	return ans;
}
int fac[N],ifac[N],pw[N],inv[N];
int C(int n,int m){
	if(0>m||m>n)return 0;
	return 1ll*fac[n]*ifac[m]%mod*ifac[n-m]%mod;
}
void init(int n=N-1){
	for(int i=fac[0]=1;i<=n;i++)fac[i]=1ll*fac[i-1]*i%mod;
	ifac[n]=qpow(fac[n]);
	for(int i=n;i>=1;i--)ifac[i-1]=1ll*ifac[i]*i%mod;
	for(int i=1;i<=n;i++)inv[i]=1ll*ifac[i]*fac[i-1]%mod;
	for(int i=pw[0]=1;i<=n;i++)pw[i]=pw[i-1]*4ll%mod;
}
int a,b,c;
int go(int a,int b,int c){
	if(min({a,b,c})<0)return 0;
	return 1ll*fac[a+b+c]*ifac[a]%mod*ifac[b]%mod*ifac[c]%mod;
}
int calc(int n,int k){
	return 1ll*pw[n]*(k+k+1)%mod*inv[n+k+1]%mod*inv[n+n+k+k+1]%mod*C(k+k,k)%mod*C(n+n+n+k+k,n)%mod;
}
int main(){
	cin>>a>>b>>c,init();
	int ans=0;
	for(int i=0;i<b;i++){
		for(int j=0;j<=i&&j<=c;j++){
			ans=(ans+1ll*calc(j,i-j)*go(a-i,b-i-1,c-j))%mod;
		}
	}
	for(int i=0;i<c;i++){
		for(int j=0;j<=i&&j<=b;j++){
			ans=(ans+1ll*calc(j,i-j)*go(a-i,b-j,c-i-1))%mod;
		}
	}
	ans=(go(a,b,c)+mod-ans)%mod;
	cout<<ans<<endl;
	return 0;
}
#ifdef DEBUG
#include"debug.hpp"
#endif