//hash模数一定要是质数!!!!!!!! 1e18被卡了. 而且 1e18+3不对,是(ll)1e18+3
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i,j,k) for(int i=j;i<=k;++i)
#define per(i,j,k) for(int i=j;i>=k;--i)
#define IOS {cin.tie(0);cout.tie(0);ios::sync_with_stdio(0);}
#define P pair<int,int>
#define lll __int128
const int N=1e6+6,mod=998244353,bs=131;
const ll mo=(ll)1e18+1;
char s[N],t[N]; int n,m;
lll hs[N],ht[N],pw[N];
struct T{
    ll s0,s1,s2;
}dp[N],v[N];
inline int add(int x,int y){
    x+=y; if(x>=mod)x-=mod; return x;
}
inline int dif(int x,int y){
    x-=y; if(x<0)x+=mod; return x;
}
T operator +(T a,T b){
    return {add(a.s0,b.s0),add(a.s1,b.s1),add(a.s2,b.s2)};
}
T operator -(T a,T b){
    return {dif(a.s0,b.s0),dif(a.s1,b.s1),dif(a.s2,b.s2)};
}
void iniths(char s[],int n,lll h[]){
    rep(i,1,n)h[i]=(h[i-1]*bs+s[i])%mo;
}
ll cal(lll h[],int l,int r){
    --l; 
    ll res=(h[r]-h[l]*pw[r-l])%mo;
    if(res<0)res+=mo; return res;
    //直接+mod %mod被卡TLE了
}
int fd(int l1,int l2){
    int L=1,R=min(n-l1+1,m-l2+1),mid;
    while(L<=R){
        mid=L+R>>1;
        if(cal(hs,l1,l1+mid-1)==cal(ht,l2,l2+mid-1))L=mid+1;
        else R=mid-1;
    }
    return  L-1;
}
int main(){
    IOS
    pw[0]=1;
    rep(i,1,1e6)pw[i]=pw[i-1]*bs%mo;
    cin>>s+1>>t+1;
    n=strlen(s+1),m=strlen(t+1);
    iniths(s,n,hs); iniths(t,m,ht);
    T tmp={0,0,0}; dp[0]={1,0,0};
    rep(i,0,n){
        tmp=tmp+v[i];
        if(i)dp[i]=tmp;
        if(i==n)break;
        int len1=fd(i+1,1);
        if(i+1+len1<=n && 1+len1<=m){
            ++len1;
            len1+=fd(i+1+len1,1+len1);
        }
        auto [s0,s1,s2]=dp[i]; T nv={s0,(s0+s1)%mod,(s0+2*s1+s2)%mod};
        v[i+1]=v[i+1]+nv;
        v[i+1+len1]=v[i+1+len1]-nv;
    }
    cout<<dp[n].s2;
}
/*
ababaab
aba
*/