#include<array>
#include<vector>
#include<iostream>
#include<algorithm>
#include<string>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int N=1e6+1,modnum=2;
const ull base=13331,mod[modnum]={(ull)998244353,(ull)1e9+9};
ull pw[modnum][N];
void init()
{
    for(int j=0;j<modnum;++j)
    {
        pw[j][0]=1;
        for(int i=1;i<N;++i)
            pw[j][i]=pw[j][i-1]*base%mod[j];
    }
}
void initHash(string &s,vector<vector<int>> &h)
{
    h.resize(modnum);
    for(int j=0;j<modnum;++j)
    {
        h[j].resize(s.size()+1);
        h[j][0]=0;
        for(int i=0;i<s.size();++i)
            h[j][i+1]=(h[j][i]*base+s[i]-'a'+1)%mod[j];
    }
}
array<ull,modnum> subHash(vector<vector<int>> &h,int l,int r)
{
    array<ull,modnum> res;
    for(int i=0;i<modnum;++i)
        res[i]=(h[i][r]+mod[i]-h[i][l-1]*pw[i][r-l+1]%mod[i])%mod[i];
    return res;
}
vector<vector<int>> hs,ht;
string s,t;
int lcp[N];
ll suf1[N],suf2[N],suf3[N];
const ll p=998244353;
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    init();
    cin>>s>>t;
    initHash(s,hs);
    initHash(t,ht);
    int n=s.size(),m=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(ans==min(m,n-i+1))
            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+lcp[i]+mid)==subHash(ht,lcp[i]+2,lcp[i]+mid+1))
            {
                ans=mid;
                l=mid+1;
            }
            else
                r=mid-1;
        }
        lcp[i]+=ans+1;
    }
    suf1[n+1]=1;
    for(int i=n;i>=1;--i)
    {
        int l=i+1,r=i+lcp[i];
        suf1[i]=(suf1[l]-suf1[r+1])%p;
        suf2[i]=(suf2[l]-suf2[r+1])%p+(suf1[l]-suf1[r+1])%p;
        suf3[i]=(suf3[l]-suf3[r+1])%p+2*(suf2[l]-suf2[r+1])%p+(suf1[l]-suf1[r+1])%p;
        suf1[i]=(suf1[i]+suf1[i+1]+p)%p;
        suf2[i]=(suf2[i]+suf2[i+1]+p)%p;
        suf3[i]=(suf3[i]+suf3[i+1]+p)%p;
    }
    cout<<(suf3[1]-suf3[2]+p)%p;
    return 0;
}