#include<bits/stdc++.h>
#define ll long long
//#define int long long
using namespace std;

const int maxn = 1010000;
const int mod  = 998244353;

const int mod1 = 998244353;
const int mod2 = 1e9+7;
const int b1   = 31;
const int b2   = 37;

struct H
{
	int h1,h2;
	friend inline H operator +(const H &k1,const H &k2) { return (H){ (k1.h1+k2.h1)%mod1,(k1.h2+k2.h2)%mod2 }; }
	friend inline H operator -(const H &k1,const H &k2) { return (H){ (k1.h1-k2.h1+mod1)%mod1,(k1.h2-k2.h2+mod2)%mod2} ; }
	friend inline H operator *(const H &k1,const H &k2)
	{
		return (H){ (ll)k1.h1*k2.h1%mod1,(ll)k1.h2*k2.h2%mod2 };
	}
	friend inline bool operator ==(const H &k1,const H &k2){ return k1.h1==k2.h1 && k1.h2==k2.h2; }
}hs[maxn],ht[maxn],pw[maxn];
int S[maxn],T[maxn],sn,tn;

int comp(const int sl,const int sr,const int tl,const int tr)
{
	int len=sr-sl+1;
	return ( hs[sr]-hs[sl-1]*pw[len] ) == ( ht[tr]-ht[tl-1]*pw[len] ) ;
}
int calc(const int sx,const int ty)
{
	int l=1,r=min(sn-sx+1,tn-ty+1);
	while(l<=r)
	{
		const int mid = (l+r)>>1;
		if(comp(sx,sx+mid-1,ty,ty+mid-1)) l=mid+1;
		else r=mid-1;
	}
	return l-1;
}

int ext[maxn];
int f[maxn],g[maxn],h[maxn];
int f1[maxn],g1[maxn],h1[maxn];
inline void add(int &a,const int &b){ a+=b;if(a>=mod)a-=mod; }
inline void sub(int &a,const int &b){ a-=b;if(a<0)a+=mod; }

int findext(int x)
{
	int y=1;
	int len= calc(x,y);
	
	if(len)
	{
		x=x+len-1,y=y+len-1;
		if(x<sn && y<tn) x++,y++;
	}
	
	if(x<sn && y<tn)
	{
		len= calc(x+1,y+1);
		x+=len,y+=len;
	}
	return x;
}

signed main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	
	pw[0]=(H){1,1};
	pw[1]=(H){b1,b2};
	for(int i=2;i<maxn;i++) pw[i]=pw[i-1]*pw[1];
	
	string str; cin>>str;
	for(auto c:str) S[++sn]=c-'a'+1;
	cin>>str;
	for(auto c:str) T[++tn]=c-'a'+1;
	
	for(int i=1;i<=sn;i++)
		hs[i]=hs[i-1]*pw[1]+(H){S[i],S[i]};
	for(int i=1;i<=tn;i++)
		ht[i]=ht[i-1]*pw[1]+(H){T[i],T[i]};
	
	for(int i=1;i<=sn;i++) 
	{
		ext[i]=findext(i);
	//	cerr<<ext[i]<<' ';
	}
	//cerr<<endl;
	
	f[0]=1;
	for(int i=0;i<=sn;i++)
	{
		if(i)
		{
			add(f1[i],f1[i-1]);
			add(g1[i],g1[i-1]);
			add(h1[i],h1[i-1]);
			
			f[i]=f1[i];
			g[i]=g1[i];
			h[i]=h1[i];
		}
		if(ext[i+1]>=i+1)
		{
			int l=i+1,r=ext[i+1]+1;
			//i+1 ~ ext[i+1]
			add(f1[l],f[i]);
			sub(f1[r],f[i]);
			add(g1[l],(f[i]+g[i])%mod);
			sub(g1[r],(f[i]+g[i])%mod);
			add(h1[l],((ll)f[i]+g[i]+g[i]+h[i])%mod);
			sub(h1[r],((ll)f[i]+g[i]+g[i]+h[i])%mod);
		}
	}
	
	cout<<h[sn]<<endl;
	
	return 0;
}