#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double db;
// #define int long long
constexpr int N = 2e6 + 50, LOGN = 23;
constexpr ll mod = 998244353;

struct SuffixArray {
    int n;
    vector<int> sa, rk, lcp;
    SuffixArray(const string &s) {
        n = s.length();
        sa.resize(n);
        lcp.resize(n - 1);
        rk.resize(n);
        iota(sa.begin(), sa.end(), 0);
        sort(sa.begin(), sa.end(), [&](int a, int b) {return s[a] < s[b];});
        rk[sa[0]] = 0;
        for (int i = 1; i < n; ++i)
            rk[sa[i]] = rk[sa[i - 1]] + (s[sa[i]] != s[sa[i - 1]]);
        int k = 1;
        vector<int> tmp, cnt(n);
        tmp.reserve(n);
        while (rk[sa[n - 1]] < n - 1) {
            tmp.clear();
            for (int i = 0; i < k; ++i)
                tmp.push_back(n - k + i);
            for (auto i : sa)
                if (i >= k)
                    tmp.push_back(i - k);
            fill(cnt.begin(), cnt.end(), 0);
            for (int i = 0; i < n; ++i)
                ++cnt[rk[i]];
            for (int i = 1; i < n; ++i)
                cnt[i] += cnt[i - 1];
            for (int i = n - 1; i >= 0; --i)
                sa[--cnt[rk[tmp[i]]]] = tmp[i];
            swap(rk, tmp);
            rk[sa[0]] = 0;
            for (int i = 1; i < n; ++i)
                rk[sa[i]] = rk[sa[i - 1]] + (tmp[sa[i - 1]] < tmp[sa[i]] || sa[i - 1] + k == n || tmp[sa[i - 1] + k] < tmp[sa[i] + k]);
            k *= 2;
        }
        for (int i = 0, j = 0; i < n; ++i) {
            if (rk[i] == 0) {
                j = 0;
            } else {
                for (j -= j > 0; i + j < n && sa[rk[i] - 1] + j < n && s[i + j] == s[sa[rk[i] - 1] + j]; )
                    ++j;
                lcp[rk[i] - 1] = j;
            }
        }
    }
};


namespace RMQ{
    ll sum[N], table[N][LOGN];
    int LOG2[N];
    void init(int n){
        for(int i = 0; i < n; i++) table[i][0] = i;
        LOG2[0] = -1;
        for (int i = 1; i < n; i++) LOG2[i] = LOG2[i >> 1] + 1;
        LOG2[0] = 0;
        for(int j = 1; (1 << j) <= n; j++)
            for(int i = 0; i + (1 << j) - 1 < n; i++){
                int x = table[i][j - 1], y = table[i + (1 << (j - 1))][j - 1];
                table[i][j] = sum[x] < sum[y] ? x : y;
            }
    }
    int query(int l, int r){
        if (l > r) swap(l, r);
        r--;
        int k = LOG2[r - l + 1];
        int x = table[l][k], y = table[r - (1 << k) + 1][k];
        return sum[x] < sum[y] ? x : y;
    }
}

void solve(){
    string s, t;cin >> s >> t;
    int n = s.size(), m = t.size();
    string ns = s + t;
    SuffixArray sa(ns);
    for (int i = 0; i < n + m; i++) RMQ::sum[i] = sa.lcp[i];
    RMQ::init(n + m);
    vector<int> R(n);
    for (int i = 0; i < n; i++) {
        int lcp = sa.lcp[RMQ::query(sa.rk[i], sa.rk[n])];     
        if (i + lcp + 1 < n && n + lcp + 1 < n + m)
            R[i] = lcp + 1 + sa.lcp[RMQ::query(sa.rk[i + lcp + 1], sa.rk[n + lcp + 1])];
        else 
            R[i] = lcp + 1;
        R[i] = min({R[i], m, n - i});
    }
    vector<ll> sum1(n + 2), sum2(n + 2), sum3(n + 3);
    sum1[n] = 1;
    for (int i = n - 1; i >= 0; i--) {
        int l = i + 1, r = i + R[i];
        sum1[i] = (2 * sum1[l] - sum1[r + 1]) % mod;
        sum2[i] = (2 * sum2[l] - sum2[r + 1] + sum1[l] - sum1[r + 1]) % mod;
        sum3[i] = (2 * sum3[l] - sum3[r + 1] + 2 * (sum2[l] - sum2[r + 1]) + sum1[l] - sum1[r + 1]) % mod;
    }
    cout << ((sum3[0] - sum3[1]) % mod + mod) % mod<< '\n';
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr), cout.tie(nullptr);
    cout << setprecision(15) << fixed;
    int t = 1;
    //cin >> t;
    while (t--) solve();
    return 0;
}