#include <bits/stdc++.h>


using namespace std;


#define ll __int128_t
#define flt double
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()


mt19937 rnd(234);
const ll inf = 1e18;
flt eps = 1e-9;


int n, m;
string s, t;
const ll p = 1234125345;
const ll mod = 1e18 + 3;

const ll p3 = 1234124;
const ll mod3 = 1e18 + 9;
vector<ll> pw, hs, ht;
vector<ll> pw3, hs3, ht3;



int32_t main() {
    if (1) {
        ios::sync_with_stdio(0);
        cin.tie(0);
        cout.tie(0);
    }
    cin >> s >> t;
    n = (int)s.size();
    m = (int)t.size();
    pw.resize(n + m + 1);
    pw[0] = 1;
    for (int i = 1; i <= n + m; i += 1) {
        pw[i] = (pw[i - 1] * p) % mod;
    }
    pw3.resize(n + m + 1);
    pw3[0] = 1;
    for (int i = 1; i <= n + m; i += 1) {
        pw3[i] = (pw3[i - 1] * p) % mod3;
    }
    hs.resize(n + 1);
    hs[0] = 0;
    for (int i = 0; i < n; i += 1) {
        hs[i + 1] = (hs[i] * p + s[i] - 'a' + 1) % mod;
    }
    ht.resize(m + 1);
    ht[0] = 0;
    for (int i = 0; i < m; i += 1) {
        ht[i + 1] = (ht[i] * p + t[i] - 'a' + 1) % mod;
    }
    hs3.resize(n + 1);
    hs3[0] = 0;
    for (int i = 0; i < n; i += 1) {
        hs3[i + 1] = (hs3[i] * p + s[i] - 'a' + 1) % mod3;
    }
    ht3.resize(m + 1);
    ht3[0] = 0;
    for (int i = 0; i < m; i += 1) {
        ht3[i + 1] = (ht3[i] * p + t[i] - 'a' + 1) % mod3;
    }
    auto get_s = [&](int l, int r) {
        r += 1;
        ll a = ((hs[r] - hs[l] * pw[r - l]) % mod + mod) % mod;
        ll b = ((hs3[r] - hs3[l] * pw3[r - l]) % mod3 + mod3) % mod3;
        return make_pair(a, b);
        };
    auto get_t = [&](int l, int r) {
        r += 1;
        ll a = ((ht[r] - ht[l] * pw[r - l]) % mod + mod) % mod;
        ll b = ((ht3[r] - ht3[l] * pw3[r - l]) % mod3 + mod3) % mod3;
        return make_pair(a, b);
        };
    auto get_bound = [&](int i) {
        int tl = i - 1;
        int tr = min(n, i + m);
        while (tl + 1 < tr) {
            int tm = (tl + tr) / 2;
            if (get_s(i, tm) == get_t(0, tm - i)) {
                tl = tm;
            } else {
                tr = tm;
            }
        }
        if (tr == n or tr == i + m) {
            return tr - 1;
        }
        if (tr + 1 == n or tr + 1 == i + m) {
            return tr;
        }
        int bound = tr + 1;
        tl = bound - 1;
        tr = min(n, i + m);
        while (tl + 1 < tr) {
            int tm = (tl + tr) / 2;
            if (get_s(bound, tm) == get_t(bound - i, tm - i)) {
                tl = tm;
            } else {
                tr = tm;
            }
        }
        return tr - 1;
        };
    vector<ll> p0(n + 2, 0), p1(n + 2, 0), p2(n + 2, 0);
    auto mod2 = [&](ll x) {
        ll f = 998244353;
        return (x % f + f) % f;
        };
    p0[n] = -1;
    for (int i = n - 1; i >= 0; i -= 1) {
        int bound = get_bound(i);
        ll sm0 = mod2(p0[bound + 2] - p0[i + 1]);
        ll sm1 = mod2(p1[bound + 2] - p1[i + 1]);
        ll sm2 = mod2(p2[bound + 2] - p2[i + 1]);
        p0[i] = mod2(p0[i + 1] - (sm0));
        p1[i] = mod2(p1[i + 1] - (sm0 + sm1));
        p2[i] = mod2(p2[i + 1] - (sm0 + 2 * sm1 + sm2));
    }
    cout << (long long)(mod2(p2[1] - p2[0])) << "\n";
    return 0;
}