#define MD 998244353
Comb<Mint>c;
ll@n,@m,@a[n],@b[n];
Mint e[m][1024];
rep(k,m){
	rep(j,601){
		e[k][j]=1;
	}
}
rep(i,n){
	rep(j,601){
		e[i%m][j]*=c.C(a[i]+b[i],j-300+b[i]);
	}
}
Mint g[1<<17];
g[0]=1;
rep(k,m){
	convolution(g,1<<17,e[k],1024,g,1<<17);
}
wt(g[m*300]);