#include<bits/stdc++.h>
using namespace std;
const int N = 1e6 + 15, P = 998244353;
const int B = 29, P1 = 1e9 + 7, P2 = 1e9 + 9;
char s[N], t[N];
int n, m;
int bp[N][2];
int sha[N][2], tha[N][2];
int to[N], lcp[N];
int f[N][3], fs[N][3];
pair<int, int> getha(int h[N][2], int l, int r) {
    int len = r - l + 1;
    int h1 = (h[r][0] - 1ll * h[l - 1][0] * bp[len][0] % P1 + P1) % P1;
    int h2 = (h[r][1] - 1ll * h[l - 1][1] * bp[len][1] % P2 + P2) % P2;
    return make_pair(h1, h2);
}
int glcp(int i, int j) {
    if (i > n || j > m) return 0;
    int l = 0, r = min(n - i + 1, m - j + 1), mid = 0;
    while (l < r) {
        mid = (l + r + 1) >> 1;
	if (getha(sha, i, i + mid - 1) == getha(tha, j, j + mid - 1)) l = mid;
        else r = mid - 1;
    }
    return l;
}
signed main() {
    scanf("%s%s", s + 1, t + 1);
    n = strlen(s + 1), m = strlen(t + 1);
    bp[0][0] = bp[0][1] = 1;
    for(int i = 1; i <= n; ++i) {
        sha[i][0] = (1ll * sha[i - 1][0] * B + (s[i] - 'a')) % P1, sha[i][1] = (1ll * sha[i - 1][1] * B + (s[i] - 'a')) % P2;
        tha[i][0] = (1ll * tha[i - 1][0] * B + (t[i] - 'a')) % P1, tha[i][1] = (1ll * tha[i - 1][1] * B + (t[i] - 'a')) % P2;
        bp[i][0] = 1ll * bp[i - 1][0] * B % P1, bp[i][1] = 1ll * bp[i - 1][1] * B % P2;
    }
    for(int i = 1; i <= n; ++i) {
        int l1 = 0, l2 = 0;
        l1 = glcp(i, 1);
        if (i + l1 - 1 == n || l1 == m) to[i] = i + l1 - 1;
        else {
            l2 = glcp(i + l1 + 1, 1 + l1 + 1);
            to[i] = i + l1 + 1 + l2 - 1;
        }
    }
    f[n + 1][0] = fs[n + 1][0] = 1;
    for(int i = n; i >= 1; --i) {
        int s0 = (fs[i + 1][0] - fs[to[i] + 1 + 1][0] + P) % P, s1 = (fs[i + 1][1] - fs[to[i] + 1 + 1][1] + P) % P, s2 = (fs[i + 1][2] - fs[to[i] + 1 + 1][2] + P) % P;
        f[i][0] = s0, f[i][1] = (s1 + s0) % P, f[i][2] = (1ll * s2 + 2ll * s1 + 1ll * s0) % P;
        for(int j = 0; j <= 2; ++j) fs[i][j] = (fs[i + 1][j] + f[i][j]) % P;
    }
    printf("%d\n", f[1][2]);
    return 0;
}