#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=n-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[8]={1,0,-1,0,1,1,-1,-1};
const ll dx[8]={0,-1,0,1,1,-1,1,-1};
template<class T> inline bool chmin(T& a, T b) {
    if (a >= b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

const int mod = MOD9;
const int max_n = 200005;
struct mint {
  ll x; // typedef long long ll;
  mint(ll x=0):x((x%mod+mod)%mod){}
  mint operator-() const { return mint(-x);}
  mint& operator+=(const mint a) {
    if ((x += a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator-=(const mint a) {
    if ((x += mod-a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this;}
  mint operator+(const mint a) const { return mint(*this) += a;}
  mint operator-(const mint a) const { return mint(*this) -= a;}
  mint operator*(const mint a) const { return mint(*this) *= a;}
  mint pow(ll t) const {
    if (!t) return 1;
    mint a = pow(t>>1);
    a *= a;
    if (t&1) a *= *this;
    return a;
  }
 
  // for prime mod
  mint inv() const { return pow(mod-2);}
  mint& operator/=(const mint a) { return *this *= a.inv();}
  mint operator/(const mint a) const { return mint(*this) /= a;}
};
istream& operator>>(istream& is, mint& a) { return is >> a.x;}
ostream& operator<<(ostream& os, const mint& a) { return os << a.x;}

struct combination {
  vector<mint> fact, ifact;
  combination(int n):fact(n+1),ifact(n+1) {
    assert(n < mod);
    fact[0] = 1;
    for (int i = 1; i <= n; ++i) fact[i] = fact[i-1]*i;
    ifact[n] = fact[n].inv();
    for (int i = n; i >= 1; --i) ifact[i-1] = ifact[i]*i;
  }
  mint operator()(int n, int k) {
    if (k < 0 || k > n) return 0;
    return fact[n]*ifact[k]*ifact[n-k];
  }
  mint P(int n, int k){
    return fact[n]*ifact[n-k];
  }
}comb(max_n);

int solve(string s){
    vector<string> seen;
    queue<string> que;
    que.push(s);
    seen.pb(s);
    while(!que.empty()){
        string now=que.front();que.pop();
        rep(i,s.size()-1){
            if(now[i]!=now[i+1]){
                string next=now;
                set<char> use;rep(k,3)use.insert('a'+k);
                use.erase(now[i]);use.erase(now[i+1]);
                next[i]=*use.begin();next[i+1]=*use.begin();
                bool ok=true;
                for(auto z:seen){
                    if(z==next)ok=false;
                }
                if(ok){
                    seen.push_back(next);
                    que.push(next);
                }
            }
        }
    }
    return (int)seen.size();
}
int main(){
    string s;cin >> s;
    bool alsame=true,aldif=true;
    rep(i,s.size()-1){
        if(s[i]!=s[i+1])alsame=false;
        else aldif=false;
    }
    if(alsame)cout << 1 <<endl,exit(0);
    if(s.size()<=3){
        cout << solve(s) <<endl;return 0;
    }
    ll m=0;
    rep(i,s.size())m+=s[i]-'a';m%=3;
    mint dp[s.size()+1][2][3][3];//連続/末尾/mod;
    dp[1][0][0][0]=1;dp[1][0][1][1]=1;dp[1][0][2][2]=1;
    rep(i,s.size()){
        rep(j,3)rep(k,3)rep(l,3){
            dp[i+1][1][l][(k+l)%3]+=dp[i][1][j][k];
        }
        rep(j,3)rep(k,3)rep(l,3){
            if(j==l){
                dp[i+1][1][l][(k+l)%3]+=dp[i][0][j][k];
            }
            else{
                dp[i+1][0][l][(k+l)%3]+=dp[i][0][j][k];
            }
        }
    }
    mint ans=0;
    rep(i,3){
        ans+=dp[s.size()][1][i][m];
    }
    if(aldif)ans+=1;
    cout << ans <<endl;
}

Measured memory_bytes: 34800