#include<bits/stdc++.h>
#define Gc() getchar()
#define Me(x,y) memset(x,y,sizeof(x))
#define Mc(x,y) memcpy(x,y,sizeof(x))
#define d(x,y) ((m)*(x-1)+(y))
#define R(n) (rnd()%(n)+1)
#define Pc(x) putchar(x)
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define eb emplace_back
#define all(x) x.begin(),x.end()
using namespace std;using ll=long long;using db=double;using lb=long db;using ui=unsigned;using ull=unsigned long long;using pii=pair<int,int>;
const int N=300+5,M=(1<<20)+5,K=1000+5,mod=998244353,Mod=mod-1;const db eps=1e-9;const ll INF=1e18+7;mt19937 rnd(263082);
#define Tp template<typename T>
#define Ts template<typename T,typename... Ar>
namespace Debug{
	Tp void _debug(char* f,T t){cerr<<f<<'='<<t<<endl;}
	Ts void _debug(char* f,T x,Ar... y){while(*f!=',') cerr<<*f++;cerr<<'='<<x<<",";_debug(f+1,y...);}
	#ifdef LOCAL
	#define gdb(...) _debug((char*)#__VA_ARGS__,__VA_ARGS__)
	#else 
	#define gdb(...) void()
	#endif
}using namespace Debug;

int n,m,A[N];
char s[N*2];
ll f[N][N][2],g[N][N][2];
void Solve(){
	scanf("%d%d%s",&n,&m,s+1);
	for(int i=1;i<=m;i++) scanf("%d",&A[i]);
	int c1=0,c2=0;
	f[m][0][0]=1;
	for(int i=1;i<=n+m;i++){
		Mc(g,f);Me(f,0);
		if(s[i]=='-'){
			c2++;
			for(int x=0;x<=m;x++) for(int y=max(0,c1-(n-A[x]));y<=x&&y+m-x<=c1;y++)if(y+m-x>=c2){
				for(int o:{0,1}){
					if(y+m-x==c2&&o) {
						ll w=g[x][y][o];
						for(int z=x-1;~z&&y>=x-z;z--){
							(f[z][y-(x-z)][0]+=w)%=mod;
							(w*=y-(x-z))%=mod;
						} 
					}else{
						(f[x][y][o]+=g[x][y][o])%=mod;
					}
				}
			}
		}else{
			for(int x=0;x<=m;x++) for(int y=max(0,c1-(n-A[x]));y<=x&&y+m-x<=c1;y++)for(int o:{0,1}){
				(f[x][y+1][o]+=g[x][y][o])%=mod;
				if(!o&&x) (f[x][y+1][1]+=g[x][y][0])%=mod;
				(f[x][y][o]+=g[x][y][o]*(n-A[x]-(c1-y)))%=mod;
			}
			c1++;
		}
	}
	printf("%lld\n",f[0][0][0]);
}
int main(){
	int t=1;
	// scanf("%d",&t);
	while(t--) Solve();
	cerr<<clock()*1.0/CLOCKS_PER_SEC<<'\n';
}