#include<bits/stdc++.h>
using namespace std;
const int MOD = 998244353;
int qpow(int a,int b){
	int res = 1;
	for( ; b; b >>= 1){
		if(b & 1) res = 1LL * res * a % MOD;
		a = 1LL * a * a % MOD;
	}
	return res;
}
/*
struct edge{
	int to,nxt;
}e[200010];
int nE = 0,hd[200010];
void add(int u,int v){
	e[++nE] = (edge){v,hd[u]};
	hd[u] = ++nE;
}
int fa[200010];
int Find(int i){
	return fa[i] == i ? i : fa[i] = Find(fa[i]);
}
void Unite(int u,int v){
	u = Find(u),v = Find(v);
	if(u == v) return;
	fa[u] = v;
}
int bit[200010];
int LSB(int i){
	return i & (-i);
}
void upd(int i,int v){
	while(i <= n){
		bit[i] += v;
		i += LSB(i);
	}
}
int psq(int i){
	int res = 0;
	while(i){
		res += bit[i];
		i -= LSB(i);
	}
}
*/
int x,y,z;
int f[10010][10010],fac[30010],ifac[30010],inv[30010];
int C(int a,int b,int c){
	if(a < 0 || b < 0 || c < 0) return 0;
	return 1LL * fac[a + b + c] * ifac[a] % MOD * ifac[b] % MOD * ifac[c] % MOD;
}
int main(){
	fac[0] = 1;
	for(int i = 1; i < 30010; i++) fac[i] = 1LL * fac[i - 1] * i % MOD;
	ifac[30009] = qpow(fac[30009],MOD - 2);
	for(int i = 30008; i >= 0; i--) ifac[i] = 1LL * ifac[i + 1] * (i + 1) % MOD;
	for(int i = 0; i <= 10002; i++) f[i][0] = 1LL * fac[2 * i] * ifac[i] % MOD * ifac[i + 1] % MOD;
	inv[1] = 1;
	for(int i = 2; i < 30010; i++) inv[i] = 1LL * (MOD - MOD / i) * inv[MOD % i] % MOD;
	for(int i = 1; i <= 10002; i++){
		for(int j = 1; j < i; j++) f[i][j] = (f[i - 1][j] + f[j][j]) % MOD;
		f[i][i] = 2LL * inv[i] % MOD;
	}
	for(int i = 1; i <= 10002; i++){
		int tmp1 = 2 * i + 1,tmp2 = 2 * i + 1,tmp = f[i][0];
		for(int j = 1; j <= i; j++){
			int coef = 1LL * tmp1 * inv[tmp2] % MOD;
			tmp = 1LL * tmp * f[i][j] % MOD * coef % MOD;
			f[i][j] = tmp;
			tmp1++,tmp2 -= 2;
		}
	}
	scanf("%d %d %d",&x,&y,&z);
	int ans = C(x,y,z);
	//(a,a,b)
	for(int a = 0; a + 1 <= y; a++){
		for(int b = 0; b <= min(a,z); b++){
			//(a,a + 1,b)
			int coef = 1LL * f[a][b] * C(x - a,y - a - 1,z - b) % MOD;
			ans = (ans - coef) % MOD;
		}
	}
	//(b,a,b)
	for(int b = 0; b + 1 <= z; b++){
		for(int a = 0; a <= min(b,y); a++){
			//(b,a,b + 1)
			int coef = 1LL * f[b][a] * C(x - b,y - a,z - b - 1) % MOD;
			ans = (ans - coef) % MOD;
		}
	}
	printf("%d",(ans + MOD) % MOD);
    return 0;
}