#include<bits/stdc++.h>
#include<atcoder/all>
#define all(a) begin(a),end(a)
#define fin(...) rr vo(pp(__VA_ARGS__))
#define ep(...) emplace(__VA_ARGS__)
#define eb(...) emplace_back(__VA_ARGS__)
#define ef(...) else if(__VA_ARGS__)
#define wh(...) while(__VA_ARGS__)
#define fo1(a) for(ll ii=0,stop=a;ii<stop;++ii)
#define fo(i,...) for(ll i=rng_fo(__VA_ARGS__)[0],stop=rng_fo(__VA_ARGS__)[1],step=rng_fo(__VA_ARGS__)[2];i<stop;i+=step)
#define of(i,...) for(ll i=rng_of(__VA_ARGS__)[0],stop=rng_of(__VA_ARGS__)[1],step=rng_of(__VA_ARGS__)[2];i>=stop;i-=step)
#define ov4(a,b,c,d,e,...) e
#define fe2(v,e) for(auto&&e:v)
#define fe3(v,...) for(auto&&[__VA_ARGS__]:v)
#define fe(v,...) ov4(__VA_ARGS__,fe3,fe3,fe3,fe2)(v,__VA_ARGS__)
#define RD(T,...) T __VA_ARGS__;li(__VA_ARGS__)
#define LL(...) RD(ll,__VA_ARGS__)
#define ST(...) RD(str,__VA_ARGS__)
#define UL(n,...) u1 __VA_ARGS__;resize({n},__VA_ARGS__);li(__VA_ARGS__)
#define UV(n,...) u1 __VA_ARGS__;resize({n},__VA_ARGS__);vi(__VA_ARGS__)
#define U2(n,m,...) u2 __VA_ARGS__;resize({n,m},__VA_ARGS__);li(__VA_ARGS__)
#define SS(n,...) strs __VA_ARGS__;resize({n},__VA_ARGS__);li(__VA_ARGS__)
#define I(...) template<__VA_ARGS__>
#define J typename
#define O operator
#define ce constexpr
#define cs const
#define rr return
#define uu using
void solve();uu is=std::istream;uu os=std::ostream;uu std::cin;uu std::cout;uu std::swap;uu std::lower_bound;uu std::upper_bound;
uu std::vector;uu std::map;uu std::set;uu std::multiset;uu std::deque;uu std::priority_queue;I(J T)uu inil=std::initializer_list<T>;
uu std::tuple;uu std::array;uu std::begin;uu std::end;
uu vo=void;uu bo=bool;uu dd=long double;uu ll=long long;uu i64=ll;uu i128=__int128_t;uu ul=unsigned long long;uu u64=ul;uu u128=__uint128_t;
I(J T)uu v1=vector<T>;I(J T)uu v2=v1<v1<T>>;uu u1=v1<ll>;uu u2=v2<ll>;uu str=std::string;uu strs=v1<str>;str sp=" ",nc="",nl="\n";
uu ml=atcoder::modint998244353;is&O>>(is&i,ml&x){ll t;i>>t;x=t;rr i;}os&O<<(os&o,cs ml&x){rr o<<x.val();}uu m1=v1<ml>;uu m2=v2<ml>;
I(J A,J B=A)struct cp{
  A a;B b;cp():a(),b(){}cp(A a,B b):a(a),b(b){}cp(std::pair<A,B>p):a(p.first),b(p.second){}cp O-()cs{rr cp(-a,-b);}
  cp&O+=(cs cp&c){a+=c.a,b+=c.b;rr*this;}cp O+(cs cp&c)cs{rr cp{*this}+=c;}bo O==(cs cp&c)cs{rr a==c.a&&b==c.b;}
  cp&O-=(cs cp&c){a-=c.a,b-=c.b;rr*this;}cp O-(cs cp&c)cs{rr cp{*this}-=c;}bo O!=(cs cp&c)cs{rr a!=c.a||b!=c.b;}
  bo O<(cs cp&c)cs{rr a!=c.a?a<c.a:b<c.b;}bo O>=(cs cp&c)cs{rr!(*this<c);}friend is&O>>(is&i,cp&c){rr i>>c.a>>c.b;}
  bo O>(cs cp&c)cs{rr a!=c.a?a>c.a:b>c.b;}bo O<=(cs cp&c)cs{rr!(*this>c);}friend os&O<<(os&o,cs cp&c){rr o<<c.a<<sp<<c.b;}
};uu cl=cp<ll>;uu cls=v1<cl>;
I(J T)uu qmax=priority_queue<T>;I(J T)uu qmin=priority_queue<T,v1<T>,std::greater<T>>;uu dl=deque<ll>;I(J T)uu uset=std::unordered_set<T>;
I(J T)struct mset:multiset<T>{uu multiset<T>::multiset;vo erase(cs T&x){if(this->count(x))multiset<T>::erase(this->find(x));}};
I(J T,J U)uu umap=std::unordered_map<T,U>;uu mp=map<ll,ll>;uu ump=umap<ll,ll>;uu sl=set<ll>;uu usl=uset<ll>;uu msl=mset<ll>;
I(J T)ce bo is_vec=0;I(J T)ce bo is_vec<v1<T>> =1;I(J T)ce bo is_pq=0;I(J T)ce bo is_pq<qmax<T>> =1;I(J T)ce bo is_pq<qmin<T>> =1;
ce ll oo=3e18;dd ee=1e-12,pi=acosl(-1);u1 dx{-1,0,1,0,-1,1,1,-1},dy{0,-1,0,1,-1,-1,1,1};str Yes(bo y=1){rr y?"Yes":"No";}
ul rnd(){static ul x=76,y=53,z=20,w=41;ul t=(x^(x<<11));x=y,y=z,z=w;rr(w=(w^(w>>19))^(t^(t>>8)));}str No(){rr Yes(0);}
ll rnd_rng(ll r){rr rnd()%r;}ll rnd_rng(ll l,ll r){rr rnd()%(r-l)+l;}I(J T,J U,J V)bo in(T l,U m,V r){rr l<=m&&m<r;}
array<ll,3>rng_fo(ll a=oo,ll b=oo,ll c=oo){if(b==oo)rr{0,a,1};if(c==oo)rr{a,b,1};rr{a,b,c};}
array<ll,3>rng_of(ll a=oo,ll b=oo,ll c=oo){if(b==oo)rr{a-1,0,1};if(c==oo)rr{a-1,b,1};rr{a-1,b,c};}

bo odd(ll x){rr x&1;}bo eve(ll x){rr~x&1;}ll pm1(ll x){rr 1-2*(x&1);}ll pw2(ll n){rr 1LL<<n;}ll rng1(ll l,ll r){rr pw2(r)-pw2(l);}
ll rng_bit(ll x,ll l,ll r){rr rng1(l,r)&x;}ll ppc(ll x,ll l=0,ll r=63){rr __builtin_popcountll(rng_bit(x,l,r));}
ll msb(ll x){rr x?63-__builtin_clzll(x):-1;}ll l2(u128 x){x|=1;ll r=0;wh(x)x>>=1,++r;rr r;}I(J T)T sq(cs T&a){rr a*a;}
ll lsb(ll x){rr x?__builtin_ctzll(x):-1;}ll l10(u128 x){x|=1;ll r=0;wh(x)x/=10,++r;rr r;}I(J T)T cb(cs T&a){rr a*a*a;}
I(J T)ll len(cs T&a){rr a.size();}I(J T)auto zt(v1<T>a){fo(i,1,len(a))a[i]+=a[i-1];rr a;}
I(J T)bo bit(T x,ll i){rr x>>i&1;}I(J T)auto at(cs T&a,ll i){ll n=len(a);rr a[(i%n+n)%n];}u1 io(ll n,ll x=0){u1 a(n);iota(all(a),x);rr a;}
I(J T)T flo(T x,T y){rr y<0?x=-x,y=-y:x>=0?x/y:(x+1)/y-1;}I(J T)ll sgn(cs T&a){rr(a>ee)-(a<-ee);}
I(J T)T cei(T x,T y){rr y<0?x=-x,y=-y:x<=0?x/y:(x-1)/y+1;}I(J T,J U)ll sgn(cs T&a,cs U&b){rr sgn(a-b);}

I(J T)T rect(cs v1<T>&s,ll l,ll r){assert(0<=l&&l<=r&&r<=len(s));T t{};if(r)t+=s[r-1];if(l)t-=s[l-1];rr t;}
I(J T)auto&O++(v1<T>&v,int){fe(v,e)++e;rr v;}I(J T)auto&O^=(v1<T>&v,cs v1<T>&u){copy(all(u),back_inserter(v));rr v;}
I(J T)auto&O--(v1<T>&v,int){fe(v,e)--e;rr v;}I(J T)auto O^(v1<T>v,cs v1<T>&u){rr v^=u;}
I(J T)T&srt(T&a){sort(all(a));rr a;}I(J T)T&rv(T&a){reverse(all(a));rr a;}I(J T)T slice(cs T&a,ll l,ll r){rr T(begin(a)+l,begin(a)+r);}
I(J T)T&rsr(T&a){srt(a),rv(a);rr a;}I(J T)T&uq(T&a){srt(a),a.erase(unique(all(a)),end(a));rr a;}
I(J T)auto pop(T&a){if ce(is_pq<T>){auto r=a.top();a.pop();rr r;}else{auto r=rb(a);a.pop_back();rr r;}}
I(J T)T pof(deque<T>&q){T r=bg(q);q.pop_front();rr r;}I(J T)decltype(auto)bg(T&a){rr*begin(a);}
I(J T)T pob(deque<T>&q){T r=rb(q);q.pop_back();rr r;}I(J T)decltype(auto)rb(T&a){rr*rbegin(a);}
I(J...A)auto max(cs A&...a){rr std::max(inil<std::common_type_t<A...>>{a...});}I(J T,J U=T)vo af(v1<T>&a,U e={}){a.ep(begin(a),e);}
I(J...A)auto min(cs A&...a){rr std::min(inil<std::common_type_t<A...>>{a...});}I(J T)vo df(T&a){a.erase(begin(a));}
I(J T,J U)bo amax(T&a,cs U&b){rr a<b?a=b,1:0;}I(J T,J U)ll lbs(cs v1<T>&a,cs U&b){rr lower_bound(all(a),b)-begin(a);}
I(J T,J U)bo amin(T&a,cs U&b){rr a>b?a=b,1:0;}I(J T,J U)ll ubs(cs v1<T>&a,cs U&b){rr upper_bound(all(a),b)-begin(a);}
I(J V)auto vec_defval(cs v1<V>&){if ce(is_vec<V>)rr vec_defval(V());else rr V();}I(J T)bo add(T&a,cs T&b){rr a+=b,1;}
I(J S,bo f(S&,cs S&),J V)cp<S,bo>scan(cs v1<V>&v){//semigroup
  S r{};bo b=0;if ce(std::is_same_v<V,S>)fe(v,x)b?f(r,x):(r=x,b=1);else fe(v,x)if(auto[y,c]=scan<S,f>(x);c)b?f(r,y):(r=y,b=1);rr{r,b};}
I(J V,J T=decltype(vec_defval(V())))T max(cs V&v){rr scan<T,amax<T>>(v).a;}
I(J V,J T=decltype(vec_defval(V())))T min(cs V&v){rr scan<T,amin<T>>(v).a;}
I(J V,J T=decltype(vec_defval(V())))T sum(cs V&v){rr scan<T,add<T>>(v).a;}I(J F,J...A)vo swl(cs F&f,A&...a){(vo)inil<ll>{(vo(f(a)),0)...};}
I(J T=ll,ll k=0,ll n)auto vec(cs ll(&s)[n],cs T&x={}){if ce(k==n-1)rr vector(s[k],x);else rr vector(s[k],vec<T,k+1,n>(s,x));}
I(ll n,J...A)vo resize(cs ll(&s)[n],A&...a){swl([&](auto&u){u=vec(s,vec_defval(u));},a...);}
I(J V,J T=decltype(vec_defval(V())))vo fill(v1<V>&v,T x={}){if ce(std::is_same_v<V,T>)fe(v,e)e=x;else fe(v,e)fill(e,x);}

struct fio{fio(){cin.tie(0);std::ios::sync_with_stdio(0);cout<<std::fixed<<std::setprecision(12);}}fio;
os&O<<(os&o,u128 x){if(x<10)rr o<<char(x+'0');rr o<<x/10<<char(x%10+'0');}
os&O<<(os&o,i128 x){if(x<0)x=-x,o<<'-';rr o<<u128(x);}I(J T,J U)os&O<<(os&o,cs std::pair<T,U>&p){rr o<<p.first<<sp<<p.second;}
I(J V)os&O<<(os&o,cs v1<V>&v){str s=nl;if ce(is_vec<V>){if ce(is_vec<J V::value_type>)s+=nl;}else s=sp;fe(v,e)o<<e<<(&e==&rb(v)?nc:s);rr o;}
I(J T)os&O<<(os&o,cs set<T>&v){fe(v,e)o<<e<<sp;rr o;}I(J T,J U)os&O<<(os&o,cs map<T,U>&m){fe(m,e)o<<e<<nl;rr o;}
I(J T)os&O<<(os&o,cs mset<T>&v){fe(v,e)o<<e<<sp;rr o;}I(J T)is&O>>(is&i,v1<T>&v){fe(v,e)i>>e;rr i;}
I(J T)ll pp(cs T&a){cout<<a<<nl;rr 0;}I(J...A)ll li(A&...a){(cin>>...>>a);rr 0;}I(J...A)vo vi(ll i,A&...a){(cin>>...>>a[i]);}
I(J T,J...A)ll pp(cs T&a,cs A&...b){cout<<a;((cout<<sp<<b),...);rr pp(nc);}I(J T,J...A)vo vi(v1<T>&a,A&...b){fo(i,len(a))vi(i,a,b...);}

struct edg{ll t,w;edg(){}edg(ll t,ll w=1):t(t),w(w){}};uu graph=v2<edg>;
graph tog(cs u2&a){graph g;fe(a,e){g.eb();fe(e,v)rb(g).eb(v);}rr g;}u2 tou(cs graph&g){u2 a;fe(g,e){a.eb();fe(e,v,w)rb(a).eb(v);}rr a;}
cp<u1>ygi(u2&g,ll m,bo f=1){UV(m,a,b);if(f)a--,b--;fo(i,m)g[a[i]].eb(b[i]);rr{a,b};}
cp<u1>mgi(u2&g,ll m,bo f=1){auto[a,b]=ygi(g,m,f);fo(i,m)g[b[i]].eb(a[i]);rr{a,b};}auto ti(u2&g,bo f=1){rr mgi(g,len(g)-1,f);}
u1 en(cs str&s,cs str&b="a"){ll n=len(s);u1 r(n,-1);fo(i,n)if(len(b)==1)r[i]=s[i]-b[0];else fo(j,len(b))if(s[i]==b[j])r[i]=j;rr r;}
str de(cs u1&a,cs str&b="a"){ll n=len(a);str r(n,'|');fo(i,n)if(len(b)==1)r[i]=a[i]+b[0];else fo(j,len(b))if(a[i]==j)r[i]=b[j];rr r;}
u2 en(cs strs&s,cs str&b="a"){u2 r;fe(s,e)r.eb(en(e,b));rr r;}str ins(){str s;li(s);rr s;}strs inss(ll n){strs s(n);li(s);rr s;}
strs de(cs u2&a,cs str&b="a"){ll n=len(a);strs r(n);fo(i,n)r[i]=de(a[i],b);rr r;}u1 abc(){rr en(ins());}u2 abcs(ll n){rr en(inss(n));}

I(J F)struct rec:F{rec(F&&f):F(std::forward<F>(f)){}I(J...A)decltype(auto)O()(A&&...a)cs{rr F::O()(*this,std::forward<A>(a)...);}};
I(J...A)u1 zp(A&...a){u1 v;fe({a...},e)v^=e;uq(v);swl([&](u1&u){fe(u,e)e=lbs(v,e);},a...);rr v;}
I(J F,J...A)u1 vs(cs F&f,A&...a){ll n;fe({a...},e)n=len(e);u1 o=io(n);sort(all(o),f);swl([&](u1&u){u1 c=u;fo(i,n)u[i]=c[o[i]];},a...);rr o;}
I(J F)ll bsl(cs F&f,ll o,ll n){wh(abs(o-n)>1)(f((o+n)/2)?o:n)=(o+n)/2;rr o;}ll sqr(ll x){ll r=max(sqrtl(x)-1,dd());wh(r+1<=x/(r+1))++r;rr r;}
I(J F)dd bsd(cs F&f,dd o,dd n){fo1(l2(abs(o-n)/ee))(f((o+n)/2)?o:n)=(o+n)/2;rr o;}
cls rle(cs u1&a){cls r;fe(a,e)len(r)&&e==rb(r).a?++rb(r).b,0:(r.eb(e,1),0);rr r;}cls rce(u1 a){rr rle(srt(a));}
i128 po(i128 x,u128 n,i128 m=0){i128 r=1;wh(n){if(n&1)r*=x;x*=x;if(m)r%=m,x%=m;n>>=1;}rr r;}
u1 divs(ll n){u1 r;for(ll i=1;i*i<=n;i++)if(n%i==0)r.eb(i),r.eb(n/i);rr uq(r);}
cls fact(ll n){ump m;for(ll i=2;i*i<=n;i++)wh(n%i==0)++m[i],n/=i;if(n>1)++m[n];cls r;fe(m,e)r.eb(e);rr srt(r);}

int main(){ll T=1;fo1(T)solve();}
vo solve(){
  LL(N);
  u1 s=en(ins(),"0");
  af(s);
  
  ml ans=0;
  ml t=1;
  auto dp=vec({N+1,2},ml()),su=vec({N+1,2},ml());
  fo(i,1,N+1){
    fill(dp),fill(su);
    dp[0][0]=su[0][0]=1;
    fo(j,1,N+1){
      fo(k,2){
        dp[j][k]+=su[j-1][k]-(j>=i?su[j-i][k]:0);
        if(j>=i)dp[j][s[j-i+1]?1:k]+=su[j-i][k];
      }
      
      fo(k,2)su[j][k]=su[j-1][k]+dp[j][k];
    }
    
    ans+=t*dp[N][1];
    t*=2;
  }
  pp(ans);
}