#include<iostream>
#include<cstdio>
#include<vector> 
#define N 6000001
#define mod 998244353
using namespace std;
int read()
{
    char c=0;
    int sum=0;
    while (c<'0'||c>'9') c=getchar();
    while ('0'<=c&&c<='9') sum=sum*10+c-'0',c=getchar();
    return sum;
}
void Adder(int &x,int d)
{
	x+=d;
	if (x>=mod) x-=mod;
	return;
}
string s;
int n,ans;
char c[N+1];
vector<int>E[N+1];
struct PAM
{
    int length,lst,leng[N+1],sn[N+1][10],fail[N+1],depth[N+1],sz[N+1];
    char st[N+1];
    vector<int>E[N+1];
    void init()
    {
		fail[0]=1,leng[1]=-1,length=1;
		return;
    }
    int get_fail(int p,int x)
    {
		while (st[x-leng[p]-1]!=st[x]) p=fail[p];
		return p;
    }
    void append(int x,char c)
    {
		st[x]=c;
		int p=get_fail(lst,x),q;
		if (!sn[p][c-'0']) q=++length,fail[q]=sn[get_fail(fail[p],x)][c-'0'],sn[p][c-'0']=q,leng[q]=leng[p]+2,depth[q]=depth[fail[q]]+1;
		lst=sn[p][c-'0'];
		if (x>n) sz[lst]++;
		return;
    }
    void append_fail()
    {
    	for (int i=2;i<=length;++i) E[fail[i]].push_back(i);
    	return;
	}
    void dfs(int x)
    {
    	for (int i=0;i<E[x].size();++i) dfs(E[x][i]),sz[x]+=sz[E[x][i]];
    	if (leng[x]<=n) Adder(ans,1ll*leng[x]*sz[x]%mod*sz[x]%mod);
    	return;
	}
};
PAM P;
int main()
{
    n=read(),P.init();
    for (int i=1;i<=n;++i) cin>>c[i]; 
    for (int i=1;i<=n;++i) P.append(i,c[i]);
    for (int i=1;i<=n;++i) P.append(i+n,c[i]);
    P.append_fail(),P.dfs(0),P.dfs(1),printf("%d\n",ans);
    return 0;
}