#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define int ll
#define fr first
#define se second
#define INF 0x3f3f3f3f
#define LINF 0x3f3f3f3f3f3f3f3f
#define all(x) x.begin(),x.end()
#define For(i,a,b) for(int i = a; i <= b; ++i)
#define Rep(i,a,b) for(int i = a; i >= b; --i)
using namespace std;
typedef pair<int,int> pii;
#ifdef OVAL
const int N = 2e3+10;
#else
const int N = 2e6+10;
#endif
const int mod[] = {998244353, 1000000009};
const int base = 13331;
array<int, 2> hss[N], hst[N], pw[N];
int n, m;
int rig[N];
int suf[3][N];
string s, t;
void solve()
{
	cin >> s >> t;
	n = s.size(), m = t.size();
	s = " " + s, t = " " + t;
	For(i,1,n){
		For(j,0,1){
			hss[i][j] = (hss[i-1][j]*base%mod[j] + s[i]-'a'+1)%mod[j];
		}
	}
	For(i,1,m){
		For(j,0,1){
			hst[i][j] = (hst[i-1][j]*base%mod[j] + t[i]-'a'+1)%mod[j];
		}
	}
	auto geths = [&](array<int, 2> *hs, int l, int r) -> array<int, 2> {
		return {
			(hs[r][0]-hs[l-1][0]*pw[r-l+1][0]%mod[0]+mod[0])%mod[0],
			(hs[r][1]-hs[l-1][1]*pw[r-l+1][1]%mod[1]+mod[1])%mod[1]
		};
	};
	For(i,1,n){
		int l = 1, r = min(m, n-i+1), ans = 0;
		while(l<=r){
			int mid = (l+r)>>1;
			if(geths(hss, i, i+mid-1) == geths(hst, 1, mid)){
				ans = mid;
				l = mid+1;
			}
			else r = mid-1;
		}
		// cout << i << ' ' << ans << '\n';
		rig[i] = ans;
		l = 1, r = min(m, n-i+1)-ans-1;
		if(r<0)continue;
		ans = 0;
		while(l<=r){
			int mid = (l+r)>>1;
			if(geths(hss, i+rig[i]+1, i+rig[i]+1+mid-1) == geths(hst, rig[i]+2, rig[i]+1+mid)){
				ans = mid;
				l = mid+1;
			}
			else r = mid-1;
		}
		rig[i] += ans+1;
		rig[i] = min(rig[i], m);
	}
	// For(i,1,n){
	// 	cout << i << ' ' << rig[i] << '\n';
	// }
	suf[0][n+1] = 1;
	{
		const int mod = 998244353;
		Rep(i,n,1){
			int l = i+1, r = i+rig[i];
			int x = (suf[0][l]-suf[0][r+1]+mod)%mod;
			int y = (suf[1][l]-suf[1][r+1]+mod)%mod+x;
			int z = (suf[2][l]-suf[2][r+1]+mod)%mod + 2*(suf[1][l]-suf[1][r+1]+mod)%mod + x;
			suf[0][i] = (suf[0][i+1]+x%mod)%mod;
			suf[1][i] = (suf[1][i+1]+y%mod)%mod;
			suf[2][i] = (suf[2][i+1]+z%mod)%mod;
		}
		cout << ((suf[2][1] - suf[2][2])%mod+mod)%mod << '\n';
	}
}
signed main()
{
	ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
	// freopen("in.txt", "r", stdin);
	// freopen("out.txt", "w", stdout);
	pw[0][0] = pw[0][1] = 1;
	For(i,1,N-1){
		For(j,0,1){
			pw[i][j] = pw[i-1][j]*base%mod[j];
		}
	}
	int tt = 1;
	// cin >> tt;
	For(tc,1,tt){
		solve();
	}
	return 0;
}