#include <cstdio>
int quick_power(int a,int b,int Mod){
	int ans=1;
	while(b){
		if(b&1){
			ans=1ll*ans*a%Mod;
		}
		b>>=1;
		a=1ll*a*a%Mod;
	}
	return ans;
}
const int Maxn=500000;
const int Mod=998244353;
int find_inv(int x){
	return quick_power(x,Mod-2,Mod);
}
int n,p;
int fac[Maxn+5],inv_f[Maxn+5],inv[Maxn+5];
void init(){
	fac[0]=1;
	for(int i=1;i<=Maxn;i++){
		fac[i]=1ll*fac[i-1]*i%Mod;
	}
	inv_f[Maxn]=find_inv(fac[Maxn]);
	for(int i=Maxn-1;i>=0;i--){
		inv_f[i]=1ll*inv_f[i+1]*(i+1)%Mod;
	}
	inv[1]=1;
	for(int i=2;i<=Maxn;i++){
		inv[i]=1ll*(Mod-Mod/i)*inv[Mod%i]%Mod;
	}
}
int C(int n,int m){
	return 1ll*fac[n]*inv_f[m]%Mod*inv_f[n-m]%Mod;
}
int f[Maxn+5];
int main(){
	init();
	scanf("%d%d",&n,&p);
	if((3*n+1)%4!=0){
		puts("0");
		return 0;
	}
	int m=(3*n+1)/4;
	int coef=1ll*C(n,m)*C(m,p)%Mod*fac[m-1]%Mod*fac[n-m-1]%Mod;
	coef=1ll*coef*quick_power(inv_f[3],n-m,Mod)%Mod*quick_power(inv_f[7],p,Mod)%Mod;
	int r=n-m-1-7*p;
	if(r<0){
		puts("0");
		return 0;
	}
	f[0]=1;
	for(int i=0;i<r;i++){
		int sum=0;
		for(int j=1;j<7&&j<=i+1;j++){
			sum=(sum+1ll*inv_f[j-1]*f[i+1-j])%Mod;
		}
		sum=1ll*sum*(m-p+1)%Mod;
		for(int j=1;j<7&&j<=i+1;j++){
			sum=(sum+1ll*(i+1)*(Mod-f[i-j+1])%Mod*inv_f[j])%Mod;
		}
		f[i+1]=1ll*sum*inv[i+1]%Mod;
	}
	int ans=1ll*f[r]*coef%Mod;
	printf("%d\n",ans);
	return 0;
}