#include<bits/stdc++.h>
using namespace std;
#define FOR(i,s,t) for(int i=(s),_t=(t); i<=_t; ++i)
#define DOR(i,s,t) for(int i=(s),_t=(t); i>=_t; --i)
const int N=1e6+50;
typedef long long ll;
const ll Mod=(1ll<<61)-1;
const int P=998244353;
const int base=233;
char a[N],b[N];
__int128 A[N],B[N];
__int128 h[N];
int n,m;
__int128 qa(int l,int r) {
    return (A[r]-(__int128)A[l-1]*h[r-l+1])%Mod;
}
__int128 qb(int l,int r) {
    return (B[r]-(__int128)B[l-1]*h[r-l+1])%Mod;
}
bool equ(int l1,int r1,int l2,int r2) {
    return (qa(l1,r1)-qb(l2,r2))%Mod==0;
}
// bool qry(int l,int r,int s) {
//     int k=r-l+1;
//     if(k>m-s+1) return 0;
//     return (A[r]-A[l-1]*h[k]-B[k])%Mod==0;
// }
// int find(int x) {
//     int L=x,R=n,p=x-1;
//     while(L<=R) {
//         int mid=L+R>>1;
//         if(qry(x,mid)) L=mid+1,p=mid;
//         else R=mid-1;
//     }
//     return p;
// }
int f[N];
ll g2[N],g1[N],g0[N];
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> a+1;
    cin >> b+1;
    n=strlen(a+1);
    m=strlen(b+1);
    h[0]=1;
    FOR(i,1,max(n,m)) h[i]=h[i-1]*base%Mod;
    FOR(i,1,n) A[i]=((__int128)A[i-1]*base+a[i])%Mod;
    FOR(i,1,m) B[i]=((__int128)B[i-1]*base+b[i])%Mod;
    FOR(i,1,n) {
        int l1=0;
        int L=1,R=min(n-i+1,m);
        while(L<=R) {
            int mid=L+R>>1;
            if(equ(i,i+mid-1,1,mid)) L=mid+1,l1=mid;
            else R=mid-1;
        }
        int p=i+l1-1;
        if(l1<m && p<n) {
            ++p;
            int L=l1+2,R=min(n-i+1,m);
            while(L<=R) {
                int mid=L+R>>1;
                if(equ(i+l1+1,i+mid-1,l1+2,mid)) L=mid+1,p=i+mid-1;
                else R=mid-1;
            }
        }
        f[i]=p;
    }
    g0[n+1]=1;    
    DOR(i,n,1) {
        int p=f[i];
        // cerr << i << ' ' << p << endl;
        // [i+1, p+1]
        g2[i]=(g0[i+1]-g0[p+2]+2*(g1[i+1]-g1[p+2])+(g2[i+1]-g2[p+2]))%P;
        g1[i]=(g0[i+1]-g0[p+2]+(g1[i+1]-g1[p+2]))%P;
        g0[i]=(g0[i+1]-g0[p+2])%P;
        g2[i]=(g2[i]+g2[i+1])%P;
        g1[i]=(g1[i]+g1[i+1])%P;
        g0[i]=(g0[i]+g0[i+1])%P;
    }
    ll res=g2[1]-g2[2];
    res%=P;
    if(res<0) res+=P;
    cout << res << '\n';
    return 0;
}