#include <string>
#include <vector>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<stack>
#include<queue>
#include<cmath>
#include<algorithm>
#include<functional>
#include<list>
#include<deque>
#include<bitset>
#include<set>
#include<map>
#include<unordered_map>
#include<unordered_set>
#include<cstring>
#include<sstream>
#include<complex>
#include<iomanip>
#include<numeric>
#include<cassert>
#define X first
#define Y second
#define pb push_back
#define rep(X,Y) for (int (X) = 0;(X) < (Y);++(X))
#define reps(X,S,Y) for (int (X) = S;(X) < (Y);++(X))
#define rrep(X,Y) for (int (X) = (Y)-1;(X) >=0;--(X))
#define rreps(X,S,Y) for (int (X) = (Y)-1;(X) >= (S);--(X))
#define repe(X,Y) for ((X) = 0;(X) < (Y);++(X))
#define peat(X,Y) for (;(X) < (Y);++(X))
#define all(X) (X).begin(),(X).end()
#define rall(X) (X).rbegin(),(X).rend()
#define eb emplace_back
#define UNIQUE(X) (X).erase(unique(all(X)),(X).end())
#define Endl endl

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
template<class T> using vv=vector<vector<T>>;
template<class T> ostream& operator<<(ostream &os, const vector<T> &t) {
os<<"{"; rep(i,t.size()) {os<<t[i]<<",";} os<<"}"<<endl; return os;}
template<class T,size_t n> ostream& operator<<(ostream &os, const array<T,n> &t) {
	os<<"{"; rep(i,n) {os<<t[i]<<",";} os<<"}"<<endl; return os;}
template<class S, class T> ostream& operator<<(ostream &os, const pair<S,T> &t) { return os<<"("<<t.first<<","<<t.second<<")";}
template<class S, class T,class U> ostream& operator<<(ostream &os, const tuple<S,T,U> &t) { return os<<"("<<get<0>(t)<<","<<get<1>(t)<<","<<get<2>(t)<<")";}
template<class S, class T,class U,class V> ostream& operator<<(ostream &os, const tuple<S,T,U,V> &t) { return os<<"("<<get<0>(t)<<","<<get<1>(t)<<","<<get<2>(t)<<","<<get<3>(t)<<")";}
template<class T> inline bool MX(T &l,const T &r){return l<r?l=r,1:0;}
template<class T> inline bool MN(T &l,const T &r){return l>r?l=r,1:0;}
#undef NUIP
#ifdef NUIP
#define out(args...){vector<string> a_r_g_s=s_p_l_i_t(#args, ','); e_r_r(a_r_g_s.begin(), args); }
vector<string> s_p_l_i_t(const string &s, char c){vector<string> v;int d=0,f=0;string t;for(char c:s){if(!d&&c==',')v.pb(t),t="";else t+=c;if(c=='\"'||c=='\'')f^=1;if(!f&&c=='(')++d;if(!f&&c==')')--d;}v.pb(t);return move(v);}
void e_r_r(vector<string>::iterator it) {}
template<typename T, typename... Args> void e_r_r(vector<string>::iterator it, T a, Args... args){ if(*it==" 1"||*it=="1") cerr<<endl; else cerr << it -> substr((*it)[0] == ' ', it -> length()) << " = " << a << ", "; e_r_r(++it, args...);}
#else
#define out
#endif
#ifdef __cpp_init_captures
template<typename T>vector<T> table(int n, T v){ return vector<T>(n, v);}
template <class... Args> auto table(int n, Args... args){auto val = table(args...); return vector<decltype(val)>(n, move(val));}
#endif
const ll MOD=998244353;
typedef vv<int> Graph;
struct Scc{
  stack<int> S;
  vector<int> inS,low,num;
  int time=0;
public:
  Graph dag;
  vector<int> inv;
  vv<int> scc;
  void visit(const Graph &g, int v){
    low[v] = num[v] = ++time;
    S.push(v); inS[v]=1;
    for(const int  &w:g[v]){
      if(!num[w]){
				visit(g,w);
				low[v]=min(low[v],low[w]);
      }else if(inS[w]) low[v]=min(low[v],num[w]);
    }
    if(low[v]==num[v]){
      scc.eb();
      while(1){
				int w = S.top(); S.pop(); inS[w]=0;
				scc.back().pb(w);
				if(v==w) break;
      }
    }
  }
  Scc(const Graph &g) {
    const int n = g.size();
    num.resize(n); low.resize(n); inS.resize(n);
    rep(u,n)if(!num[u]) visit(g,u);
    reverse(all(scc));
    
    inv.resize(n); dag.resize(scc.size());
    rep(i,scc.size())for(auto v:scc[i]) inv[v]=i;
    rep(i,scc.size())for(auto v:scc[i])for(auto e:g[v])
			if(inv[e]!=i)	dag[i].pb(inv[e]);
  }
};

ll modpow(ll r,ll n,ll m=MOD){
  ll re=1,d=r%m;
  if(n<0)(n%=m-1)+=m-1;
  for(;n;n/=2){
    if(n&1)(re*=d)%=m;
    (d*=d)%=m;
  }
  return re;
}
template <int mod=MOD> struct modInt{
  int v;
  modInt(int v=0):v(v){}
  modInt operator+(const modInt &n)const{return v+n.v<mod ? v+n.v : v+n.v-mod;}
  modInt operator-(const modInt &n)const{return v-n.v<0 ? v-n.v+mod : v-n.v;}
  modInt operator*(const modInt &n)const{return ll(v)*n.v%mod;}
  modInt operator/(const modInt &n)const{return ll(v)*modpow(n.v%mod,-1,mod)%mod;}
  modInt operator+(const ll &n)const{return v+n<mod ? v+n : v+n-mod;}
  modInt operator-(const ll &n)const{return v-n<0 ? v-n+mod : v-n;}
  modInt operator*(const ll &n)const{return ll(v)*(n%mod)%mod;}
  modInt operator/(const ll &n)const{return ll(v)*modpow(n%mod,-1,mod)%mod;}
  modInt& operator+=(const modInt &n){v+=n.v; if(v>=mod) v-=mod; return *this;}
  modInt& operator-=(const modInt &n){v-=n.v; if(v<0) v+=mod; return *this;}
  modInt& operator*=(const modInt &n){v=ll(v)*n.v%mod; return *this;}
  modInt& operator/=(const modInt &n){v=ll(v)*modpow(n.v,-1,mod)%mod; return *this;}
  modInt& operator+=(const ll &n){v+=n; if(v>=mod) v-=mod; return *this;}
  modInt& operator-=(const ll &n){v-=n; if(v<0) v+=mod; return *this;}
  modInt& operator*=(const ll &n){v=ll(v)*n%mod; return *this;}
  modInt& operator/=(const ll &n){v=ll(v)*modpow(n,-1,mod)%mod; return *this;}
};
template<int mod> ostream& operator<<(ostream &os,const modInt<mod> &n){return os<<n.v;};
template<int mod> modInt<mod> operator+(const ll &n,const modInt<mod> &m){return m.v+n<mod ? m.v+n : m.v+n-mod;}
template<int mod> modInt<mod> operator-(const ll &n,const modInt<mod> &m){return n-m.v<0 ? n-m.v+mod : n-m.v;}
template<int mod> modInt<mod> operator*(const ll &n,const modInt<mod> &m){return ll(m.v)*(n%mod)%mod;}
template<int mod> modInt<mod> operator/(const ll &n,const modInt<mod> &m){return ll(m.v)*modpow(n%mod,-1,mod)%mod;}
typedef modInt<MOD> mint;
template <int mod> modInt<mod> modpow(modInt<mod> r,ll n){ modInt<mod> re(1); if(n<0)(n%=mod-1)+=mod-1; for(;n;n/=2){if(n&1) re*=r; r*=r;} return re;}
vector<mint> fact,finv,inv;
mint comb(ll n,ll r){ if(n<r||r<0)return 0; return fact[n]*finv[n-r]*finv[r];}
class Doralion{
  void Modinvs(vector<mint> &re,int n){ re.resize(n+1); re[1]=1; for(int i=2;i<=n;++i)re[i]=re[MOD%i]*(MOD-MOD/i);}
  void Facts(vector<mint> &re,int n){ re.resize(n+1); re[0]=1; rep(i,n)re[i+1]=re[i]*(i+1);}
  void Factinvs(vector<mint> &re,const vector<mint> &inv,int n){ re.resize(n+1); re[0]=1; rep(i,n)re[i+1]=re[i]*inv[i+1];}
public:
  Doralion(int n){ Modinvs(inv,n); Facts(fact,n); Factinvs(finv,inv,n);}
} doralion(212345);

mint dp[212345][3][3];

void test(){
	const int L=7;
	int n=1; rep(i,L) n*=3;
	Graph g(n);
	auto tostr=[&](int x){
		string re;
		rep(i,L){
			re+=string(1,'a'+x%3);
			x/=3;
		}
		return re;
	};
	auto toint=[&](string s){
		int re=0;
		rrep(i,L){
			re*=3;
			re+=s[i]-'a';
		}
		return re;
	};
	//rep(i,n) cout<<i<<" "<<tostr(i)<<endl;
	rep(i,n){
		string s=tostr(i);
		rep(j,L-1)if(s[j]!=s[j+1]){
			char c='a'+'b'-s[j]+'c'-s[j+1];
			auto t=s;
			t[j]=t[j+1]=c;
			g[i].pb(toint(t));
			cout<<s<<" "<<t<<endl;
		}
	}
	out(g,1);
	Scc h(g);
	for(auto v:h.scc){
		if(v.size()==1) continue;
		for(int i:v) cout<<tostr(i)<<",";cout<<endl;
	}
}

void solve(string S){
	int L=S.size();
	int n=1; rep(i,L) n*=3;
	Graph g(n);
	auto tostr=[&](int x){
		string re;
		rep(i,L){
			re+=string(1,'a'+x%3);
			x/=3;
		}
		return re;
	};
	auto toint=[&](string s){
		int re=0;
		rrep(i,L){
			re*=3;
			re+=s[i]-'a';
		}
		return re;
	};
	//rep(i,n) cout<<i<<" "<<tostr(i)<<endl;
	rep(i,n){
		string s=tostr(i);
		rep(j,L-1)if(s[j]!=s[j+1]){
			char c='a'+'b'-s[j]+'c'-s[j+1];
			auto t=s;
			t[j]=t[j+1]=c;
			g[i].pb(toint(t));
			//cout<<s<<" "<<t<<endl;
		}
	}
	out(g,1);
	int v0=toint(S);
	vector<int> vst(n); vst[v0]=1;
	queue<int> que; que.emplace(v0);
	while(que.size()){
		int v=que.front(); que.pop();
		for(int w:g[v])if(MX(vst[w],1)) que.emplace(w);
	}
	cout<<accumulate(all(vst),0)<<endl;
}

int main(){
  ios_base::sync_with_stdio(false);
  cout<<fixed<<setprecision(0);
	//test();
	string s;
	cin>>s;
	int n=s.size();
	if(n<=5){
		solve(s);
		return 0;
	}
	int unko=1;
	rep(i,n)if(s[i]!=s[0]) unko=0;
	if(unko){
		cout<<1<<endl;
		return 0;
	}
	int con=0;
	rep(i,n-1)if(s[i]==s[i+1]) con=1;
	rep(i,3) dp[1][i][i]=1;
	reps(i,1,n){
		rep(j,3)rep(sum,3)rep(prv,3)if(prv!=j) dp[i+1][(sum+j)%3][j]+=dp[i][sum][prv];
	}
	int sum=0;
	rep(i,n) sum+=s[i]-'a';
	sum%=3;
	mint re=modpow(mint(3),n-1);
	rep(i,3) re-=dp[n][sum][i];
	//rep(i,n+1){rep(j,3)rep(k,3)cout<<dp[i][j][k]<<",";cout<<endl;}
	out(re,con,1);
	cout<<re+1-con<<endl;
  return 0;
}


Measured memory_bytes: 10704