#include <bits/stdc++.h>
using namespace std;
const int N=1e6+5;
const int p=998244353;
typedef long long ll;
typedef unsigned long long ull;
const int M=2;
const ull B=233,mod[M]={1000000009,1000000901};
ull pw[M][N];

void init()
{
    for(int j=0;j<M;++j)
    {
        pw[j][0]=1;
        for(int i=1;i<N;++i)
            pw[j][i]=pw[j][i-1]*B%mod[j];
    }
}
// h[i]表示s_{0,1,...,i-1}的哈希值
void initHash(string &s,vector<vector<int>> &h)
{
    h.resize(M);
    for(int j=0;j<M;++j)
    {
        h[j].resize(s.size()+1);
        h[j][0]=0;
        for(int i=0;i<(int)s.size();++i)
            h[j][i+1]=(h[j][i]*B+s[i]-'a'+1)%mod[j];
    }
}
array<ull,M> subHash(vector<vector<int>> &h,int l,int r)
{
    array<ull,M> res;
    for(int i=0;i<M;++i)
        res[i]=(h[i][r]+mod[i]-h[i][l-1]*pw[i][r-l+1]%mod[i])%mod[i];
    return res;
}
string s,t;
vector<vector<int>> hs,ht;
int lcp[N];
ll f[N][3],diff[N][3];

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    init();
    cin>>s>>t;
    initHash(s,hs),initHash(t,ht);
    int n=(int)s.size(),m=(int)t.size();
    for(int i=1;i<=n;i++)
    {
        int ans=0,mid,l=1,r=min(m,n-i+1);
        while(l<=r)
        {
            mid=(l+r)>>1;
            if(subHash(hs,i,i+mid-1)==subHash(ht,1,mid))
            {
                ans=mid;
                l=mid+1;
            }
            else r=mid-1;
        }
        lcp[i]=ans;
        if(lcp[i]==min(n-i+1,m)) continue;
        ans=0,l=1,r=min(m,n-i+1)-lcp[i]-1;
        while(l<=r)
        {
            mid=(l+r)>>1;
            if(subHash(hs,i+lcp[i]+1,i+mid+lcp[i])==subHash(ht,1+lcp[i]+1,mid+lcp[i]+1))
            {
                ans=mid;
                l=mid+1;
            }
            else r=mid-1;
        }
        lcp[i]+=ans+1;
    }
    f[n+1][0]=1;
    for(int i=n;i;i--)
    {
        int l=i+1,r=i+lcp[i];
        f[i][0]=(f[l][0]-f[r+1][0]+p)%p;
        f[i][1]=((f[l][1]-f[r+1][1]+p)+(f[l][0]-f[r+1][0]+p))%p;
        f[i][2]=((f[l][2]-f[r+1][2]+p)+2*(f[l][1]-f[r+1][1]+p)+(f[l][0]-f[r+1][0]+p))%p;
        f[i][0]=(f[i][0]+f[i+1][0])%p;
        f[i][1]=(f[i][1]+f[i+1][1])%p;
        f[i][2]=(f[i][2]+f[i+1][2])%p;
    }
    cout<<(f[1][2]-f[2][2]+p)%p<<'\n';
    return 0;
}