#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001LL
struct combi{
	deque<mint> kaijou;
	deque<mint> kaijou_;
	
	combi(int n){
		kaijou.push_back(1);
		for(int i=1;i<=n;i++){
			kaijou.push_back(kaijou[i-1]*i);
		}
		
		mint b=kaijou[n].inv();
		
		kaijou_.push_front(b);
		for(int i=1;i<=n;i++){
			int k=n+1-i;
			kaijou_.push_front(kaijou_[0]*k);
		}
	}
	
	mint combination(int n,int r){
		if(r>n)return 0;
		mint a = kaijou[n]*kaijou_[r];
		a *= kaijou_[n-r];
		return a;
	}
	
	mint junretsu(int a,int b){
		mint x = kaijou_[a]*kaijou_[b];
		x *= kaijou[a+b];
		return x;
	}
	
	mint catalan(int n){
		return combination(2*n,n)/(n+1);
	}
	
};
combi C(500005);
int ok[200005];

mint dp[2][200005];
mint cost[200005];

void dfs(int l,int r){
	if(r-l==1){
		cost[l] += C.kaijou[l+1];
		return;
	}
	int m = (l+r)/2;
	dfs(l,m);
	vector<mint> f(m-l);
	rep(i,f.size())f[i] = cost[l+i];
	vector<mint> g(r-l+1);
	rep(i,g.size())g[i] = -C.kaijou[i+1];
	f = convolution(f,g);
	rep(i,f.size()){
		if(l+i >= m && l+i < r)cost[l+i] += f[i];
	}
	dfs(m,r);
}

void dfs2(int l,int r){
	if(r-l==1){
		if(ok[l])swap(dp[0][l],dp[1][l]);
		return;
	}
	int m = (r+l)/2;
	dfs2(l,m);
	rep(i,2){
		vector<mint> f(m-l);
		rep(j,f.size()){
			f[j] = dp[i][l+j];
		}
		vector<mint> g(r-l+1);
		rep(j,g.size())g[j] = cost[j];
		
		f = convolution(f,g);
		rep(j,f.size()){
			if(j+l >= m && j+l < r){
				dp[i][j+l] += f[j];
			}
		}
	}
	dfs2(m,r);
}

int main(){
	
	int n,m;
	cin>>n>>m;
	
	dfs(1,n+1);
	rep(i,m){
		int a;
		cin>>a;
		ok[a] = 1;
	}
	dp[0][1] = 1;
	dfs2(1,n+1);
	
	cout<<dp[0][n].val()<<endl;
	return 0;
}