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


#include "boost/multiprecision/cpp_int.hpp"
#include "boost/multiprecision/cpp_dec_float.hpp"
namespace mp = boost::multiprecision;
typedef mp::cpp_int LL;
typedef mp::number<mp::cpp_dec_float<1024>> DD;// 仮数部が1024ビットの浮動小数点数型(TLEしたら小さくする)

 
typedef long double dd;
//#define i_7 (ll)(1E9+7)
#define i_7 998244353
#define i_5 i_7-2
ll mod(ll a){
    ll c=a%i_7;
    if(c>=0)return c;
    return c+i_7;
}
typedef pair<ll,ll> l_l;
typedef pair<dd,dd> d_d;
ll inf=(ll)1E16;
#define rep(i,l,r) for(ll i=l;i<=r;i++)
#define rrep(i,r,l) for(ll i=r;i>=l;i--)
#define pb push_back
ll max(ll a,ll b){if(a<b)return b;else return a;}
ll min(ll a,ll b){if(a>b)return b;else return a;}
void Max(ll &pos,ll val){pos=max(pos,val);}//Max(dp[n],dp[n-1]);
void Min(ll &pos,ll val){pos=min(pos,val);}
void Add(ll &pos,ll val){pos=mod(pos+val);}
dd EPS=1E-9;
#define fastio ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define fi first
#define se second
#define endl "\n"  //インタラクティブで消す！！！！！！！！！！！！！！！！！！！！！
#define SORT(v) sort(v.begin(),v.end())
#define ERASE(v) v.erase(unique(v.begin(),v.end()),v.end())
#define POSL(v,x) (lower_bound(v.begin(),v.end(),x)-v.begin())
#define POSU(v,x) (upper_bound(v.begin(),v.end(),x)-v.begin())
template<class T,class S>
inline bool chmax(T &a, S b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}
template<class T,class S>
inline bool chmin(T &a, S b) {
    if(a > b) {
        a = b;
        return true;
    }
    return false;
}

void mod_print(ll k){
    ll P=1000;
    rep(y,1,P){
        ll x=mod(y*k);
        if(x+P>=i_7){
            x-=i_7;
        }
        if(abs(x)<=P){
            //cout<<x<<"/"<<y;
            cout<<setprecision(5)<<(dd)x/(dd)y;
            return;
        }
    }
    cout<<"nun"<<endl;
}
#define all(c) c.begin(),c.end()
//////////////////////////

queue<string>q;
set<string>used;

void cal(string t){
    used.insert(t);
    q.push(t);
    while(!q.empty()){
        string a=q.front();q.pop();
        ll n=a.size();
        rep(i,0,n-2){
            string nx=a;
            if(a[i]!=a[i+1]){
                bool f[3];memset(f,false,sizeof(f));
                f[a[i]-'a']=true;
                f[a[i+1]-'a']=true;
                rep(j,0,2){
                    if(f[j]==false){
                        nx[i]=nx[i+1]=(char)('a'+j);
                    }
                }
                if(used.find(nx)==used.end()){
                    used.insert(nx);
                    q.push(nx);
                }
            }
        }
    }
    cout<<used.size()<<endl;
    //for(auto x:used)cout<<x<<endl;
    //exit(0);
}



ll po(ll i,ll p){
    if(p==0)return 1;
    else{
        i=mod(i);
        if(p==1)return i;
        if(p%2==0)return po(mod(i*i),p/2);
        return mod(i*po(i,p-1));
    }
}
ll bunbo(ll n){
    return po(n,i_5);
}
void cal2(string s){
    ll n=s.size();
    bool f=false;
    rep(i,0,n-2){
        if(s[i]==s[i+1])f=true;
    }
    
    ll dp[n][3][3];memset(dp,0,sizeof(dp));
    rep(i,0,2)dp[0][i][i]=1;
    rep(i,0,n-2){
        rep(j,0,2){
            rep(k,0,2){
                rep(nx,0,2){
                    if(k==nx)continue;
                    Add(dp[i+1][(j+nx)%3][nx],dp[i][j][k]);
                }
            }
        }
    }
    
    ll cnt=0;
    rep(i,0,n-1){
        cnt+=(s[i]-'a');
    }
    cnt%=3;
    
    ll ans=po(3,n-1);
    rep(k,0,2){
        Add(ans,-dp[n-1][cnt][k]);
    }
    if(!f)ans++;
    cout<<mod(ans)<<endl;
}

int main(){fastio
    string s;cin>>s;
    bool f=true;
    rep(i,1,s.size()-1){
        if(s[0]!=s[i])f=false;
    }
    if(f){
        cout<<1<<endl;return 0;
    }
    
    if(s.size()<=4)cal(s);
    else cal2(s);
    
    return 0;
}





Measured memory_bytes: 17840