#include <bits/stdc++.h>
#define x first
#define y second
#define int long long
using namespace std;
typedef pair<int,int> PII;
const int N = 5e3+10,INF=1e16,mod = 998244353,P=131;
int get(int x)
{
    return (x%mod+mod)%mod;
}
void solve()
{
    string S,T;
    cin>>S>>T;
    int n = S.size(),m=T.size();
    vector<int>hs(n+2,0),ht(m+1,0),p(n+m+1,0);
    S='0'+S,T='0'+T;
    p[0]=1;
    for(int i=1;i<=n+m;i++)p[i]=p[i-1]*P%mod;
    for(int i=1;i<=n;i++)hs[i]=(hs[i-1]*P+S[i])%mod;
    for(int i=1;i<=m;i++)ht[i]=(ht[i-1]*P+T[i])%mod;
    vector<array<int,3>>dp(n+5,{0,0,0}),s(n+5,{0,0,0});
    dp[0][0]=1;
    for(int i=1;i<=n;i++)
    {
        int L1=i-1,L2=0;
        int l=0,r=min(n-i+1,m);
        while(l<r)
        {
            int mid = l+r+1>>1;
            if(get(hs[L1+mid]-hs[L1]*p[mid])==get(ht[L2+mid]-ht[L2]*p[mid])) l=mid;
            else    r=mid-1;
        }
        if(L1+l!=n&&L2+l!=m)
        {
            L1+=l+1,L2+=l+1;
            l=0,r=min(n-L1,m-L2);
            while(l<r)
            {
                int mid = l+r+1>>1;
                if(get(hs[L1+mid]-hs[L1]*p[mid])==get(ht[L2+mid]-ht[L2]*p[mid]))
                    l=mid;
                else    r=mid-1;            
            }
        }
        L1+=l+1,L2+=l+1;
        s[i][2]=(s[i][2]+dp[i-1][2]+2*dp[i-1][1]+dp[i-1][0])%mod;
        s[i][1]=(s[i][1]+dp[i-1][1]+dp[i-1][0])%mod;
        s[i][0]=(s[i][0]+dp[i-1][0])%mod;
        s[L1][2]=(s[L1][2]-dp[i-1][2]-2*dp[i-1][1]-dp[i-1][0])%mod;
        s[L1][1]=(s[L1][1]-dp[i-1][1]-dp[i-1][0])%mod;
        s[L1][0]=(s[L1][0]-dp[i-1][0])%mod;
        if(i>1)
        {
            dp[i][0]=(dp[i-1][0]+s[i][0])%mod;
            dp[i][1]=(dp[i-1][1]+s[i][1])%mod;
            dp[i][2]=(dp[i-1][2]+s[i][2])%mod;
        }
        else    dp[i][0]=dp[i][1]=dp[i][2]=1;
    }
    cout<<get(dp[n][2])<<"\n";
}

signed main()
{
    int T=1;
    cin.tie(0)->sync_with_stdio(false);
    //cin>>T;
    //init();
    while(T--)
    {
        solve();
    }
}