#include<bits/stdc++.h>
using namespace std;
int p[2001],ans,n,m,a,b,t=1;
void xia_search(int cur,int num){
	p[cur]=num+p[cur-1];
	if(cur==2*n&&p[cur]>=0)ans++;
	if(num==1)a--;
	if(num==-1)b--;
	if(p[cur]<0)return ;
	if(a>0){
		xia_search(cur+1,1);
	    p[cur]=num+p[cur-1];
	    a++;
	}
	if(b>0){
		xia_search(cur+1,-1);
	    p[cur]=num+p[cur-1];
	    b++;
	}
	return ;
}
int main(){
	freopen("overzero.in","r",stdin);
	freopen("overzero.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(int i=1;i<=m;i++){
		int te;
		scanf("%d",&te);
		t*=te;
	}
	a=n;b=n;
	xia_search(1,1);
	printf("%d",ans%t);
	return 0;
}