#include<bits/stdc++.h>
#define ll long long

using namespace std;
const int N=5e3;
const ll mod=998244353;
int n;
ll p;
int a[N+10];
ll f[N*2+10];
inline ll qpow(ll x,ll y){
	ll res=1;
	while(y){
		if(y&1){
			res=res*x%mod;
		}
		x=x*x%mod;
		y>>=1;
	}
	return res;
}
int main(){
	//freopen(".in","r",stdin);
	//freopen(".out","w",stdout);
	ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	cin>>n>>p;
	p=p*qpow(100,mod-2)%mod;
	for(int i=1;i<=n;++i){
		cin>>a[i];
	}
	f[n]=1;
	for(int i=n;i;--i){
		if(~a[i]){
			for(int j=n+n-i+1;j>=n-(n-i)+1;--j){
				f[j]=(f[j]*p+f[j-1]*(1+mod-p))%mod;
			}
		}
		else{
			for(int j=n-(n-i)-1;j<=n+n-i-1;++j){
				f[j]=(f[j]*p+f[j+1]*(1+mod-p))%mod;
			}
		}
		f[n]=1;
	}
	ll ans=0;
	for(int i=0;i<=n*2;++i){
		ans=(ans+f[i])%mod;
	}
	cout<<ans*qpow(n*2+1,mod-2)%mod;
	return 0;
}