#include <bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(), (x).end()
typedef long long ll;

template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    for (int i = 0; i < int(v.size()); i++) os << v[i] << (i + 1 == int(v.size()) ? "" : " ");
    return os;
}

#ifdef tabr
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") \n";
#else
#define debug(x) void(0)
#endif

struct rh {
    static const long long md = (1LL << 61) - 1;
    static long long base;
    static vector<long long> power;
    vector<long long> hash;

    long long mul(long long a, long long b) {
        return (long long) ((__int128_t) a * b % md);
    }

    rh(const string& s) {
        int n = (int) s.size();
        int cur = (int) power.size();
        if (cur < n + 1) {
            power.resize(n + 1);
            for (int i = cur; i < n + 1; i++) {
                power[i] = mul(power[i - 1], base);
            }
        }
        hash = vector<long long>(n + 1);
        for (int i = 0; i < n; i++) {
            hash[i + 1] = mul(hash[i] + s[i], base);
        }
    }

    long long get(int l, int r) {
        long long res = hash[r + 1] - mul(hash[l], power[r - l + 1]);
        if (res < 0) {
            res += md;
        }
        return res;
    }
};

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

long long rh::base = (md >> 2) + rng() % (md >> 1);
vector<long long> rh::power = vector<long long>(1, 1);

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    string s, t;
    cin >> s >> t;
    int n = (int) s.size(), m = (int) t.size();
    vector<vector<long long>> dp(3, vector<long long>(n + 2));
    vector<vector<long long>> pref(3, vector<long long>(n + 2));
    dp[0][0] = 1;
    rh hs(s), ht(t);
    // return length of lcp(s[x:] and t[y:])
    auto Find = [&](int x, int y) {
        int low = 0, high = min(n - x, m - y) + 1;
        while (high - low > 1) {
            auto mid = (high + low) >> 1;
            if (hs.get(x, x + mid - 1) == ht.get(y, y + mid - 1)) {
                low = mid;
            } else {
                high = mid;
            }
        }
        return low;
    };
    const long long mod = 998244353;
    for (int i = 0; i <= n; i++) {
        if (i) {
            for (int j = 0; j < 3; j++) {
                pref[j][i] += pref[j][i - 1];
            }
        }
        for (int j = 0; j < 3; j++) {
            dp[j][i] += pref[j][i];
            dp[j][i] %= mod;
        }
        dp[1][i] += dp[0][i];
        dp[1][i] %= mod;
        dp[2][i] += dp[1][i];
        dp[2][i] %= mod;
        if (i == n) {
            break;
        }
        int l = 0;
        l = Find(i, 0);
        l = min(l + 1, min(n - i, m));
        l += Find(i + l, l);
        // debug(l);
        for (int j = 0; j < 3; j++) {
            pref[j][i + 1] += dp[j][i];
            pref[j][i + l + 1] += mod - dp[j][i];
            pref[j][i + 1] %= mod;
            pref[j][i + l + 1] %= mod;
        }
        // debug(dp[0][i]);
        // debug(dp[1][i]);
        // debug(dp[2][i]);
        // debug(pref[0][i]);
        // debug(pref[1][i]);
        // debug(pref[2][i]);
    }
    long long ans = dp[2][n] * 2 - dp[1][n] * 3 + dp[0][n];
    ans %= mod;
    ans += mod;
    ans %= mod;
    cout << ans << '\n';
    debug(dp[0][n]);
    debug(dp[1][n]);
    debug(dp[2][n]);
    // cout << dp[0][n] << '\n';
    // cout << dp[1][n] << '\n';
    // cout << dp[2][n] << '\n';
    return 0;
}