#include<bits/stdc++.h>
using namespace std;using ll=long long;using ld=long double;using pii=pair<int,int>;
const int M=998244353,N=3e3+10;const ll inf=1e17;const double eps=1e-10;
int dp[N][N][2][2];//row/colume/[lu grid]colored(bas 1)/[lu grid]if upper belonging
void add(int&a,int b){a+=b;if(a>=M)a-=M;}
struct S
{	
	int n;ll res=0;
	vector<string>mat;
	vector<int>u0,l0,d1,r1;
	void ini()
	{
		dp[0][0][0][1]=1;cin>>n;mat.resize(n+1);mat[0]="0";
		string s;for(int i=1;i<=n;i++)mat[0]+='1',cin>>s,mat[i]="1"+s;
		u0.resize(n+1,n+1);l0=u0;d1.resize(n+1,0);r1=d1;		
	}
	void solve()
	{
		for(int i=0;i<=n;i++)for(int j=0;j<=n;j++)
		{
			char c=mat[i][j];		
			if(j)//move right
			{//row/colume/[lu grid]colored(bas 1)/[lu grid]if upper belonging
				if(c!='1')
				{
					int &a=dp[i][j][0][1];ll v=max(min(u0[j],i)-d1[j],0);//W _ hang right
					add(a,v*dp[i][j-1][0][0]%M);//W |
					add(a,v*dp[i][j-1][0][1]%M);//W _
					add(a,v*dp[i][j-1][1][0]%M);//B |
					add(a,v*dp[i][j-1][1][1]%M);//B _
				}
				if(c!='0'&&u0[j]==n+1)
				{
					int &b=dp[i][j][1][1];//B _ hang right
					add(b,dp[i][j-1][0][0]);//W |
					add(b,dp[i][j-1][0][1]);//W _
					add(b,dp[i][j-1][1][0]);//B |
					add(b,dp[i][j-1][1][1]);//B _
				}
			}
			if(i)//move down
			{//row/colume/[lu grid]colored(bas 1)/[lu grid]if upper belonging
				if(c!='1')
				{
					int &a=dp[i][j][0][0];ll v=max(min(l0[i],j)-r1[i],0);//W | hang down
					add(a,v*dp[i-1][j][0][0]%M);//W |
					//add(a,dp[i-1][j][0][1]);//W _
					add(a,v*dp[i-1][j][1][0]%M);//B |
					//add(a,dp[i-1][j][1][1]);//B _
				}								
				if(c!='0'&&l0[i]==n+1)
				{
					int &b=dp[i][j][1][0];//B | hang down
					add(b,dp[i-1][j][0][0]);//W |
					add(b,dp[i-1][j][0][1]);//W _
					add(b,dp[i-1][j][1][0]);//B |
					//add(b,dp[i-1][j][1][1]);//B _
				}				
			}	
			if(i||j)
			{
				if(c=='0')l0[i]=min(l0[i],j),u0[j]=min(u0[j],i);
				if(c=='1')r1[i]=max(r1[i],j),d1[j]=max(d1[j],i);
			}
			//cout<<i<<","<<j<<":";for(int e=0;e<2;e++)for(int f=0;f<2;f++)cout<<dp[i][j][e][f]<<"|";cout<<'\n';
		}
		int res=0;for(int e=0;e<2;e++)for(int f=0;f<2;f++)add(res,dp[n][n][e][f]);cout<<res<<'\n';
	}
};
void precal(){}
int main()
{
	//freopen("1.in","r",stdin);
	//cout<<fixed<<setprecision(12);
	ios::sync_with_stdio(0);cin.tie(0);precal();
	int t=1;//cin>>t;
	//clock_t a=clock();
	while(t--){S SS;SS.ini();SS.solve();}
	//cout<<"Time:"<<double(clock()-a)<<'\n';
}