#include <bits/stdc++.h>
#define For(i, a, b) for(int (i)=(int)(a); (i)<(int)(b); ++(i))
#define rFor(i, a, b) for(int (i)=(int)(a)-1; (i)>=(int)(b); --(i))
#define rep(i, n) For((i), 0, (n))
#define rrep(i, n) rFor((i), (n), 0)
#define fi first
#define se second
using namespace std;
typedef long long lint;
typedef unsigned long long ulint;
typedef pair<int, int> pii;
typedef pair<int, lint> pil;
typedef pair<lint, lint> pll;
template<class T> bool chmax(T &a, const T &b){if(a<b){a=b; return true;} return false;}
template<class T> bool chmin(T &a, const T &b){if(a>b){a=b; return true;} return false;}
template<class T> T div_floor(T a, T b){
    if(b < 0) a *= -1, b *= -1;
    return a>=0 ? a/b : (a+1)/b-1;
}
template<class T> T div_ceil(T a, T b){
    if(b < 0) a *= -1, b *= -1;
    return a>0 ? (a-1)/b+1 : a/b;
}

constexpr lint mod = 1e9+7;
constexpr lint INF = mod * mod;
constexpr int MAX = 100010;

template<int_fast64_t MOD> struct modint{
    using i64=int_fast64_t;
    i64 a;
    modint(const i64 a_=0): a(a_){
        if(a>MOD) a%=MOD;
        else if(a<0) (a%=MOD)+=MOD;
    }
    modint inv(){
        i64 t=1, n=MOD-2, x=a;
        while(n){
            if(n&1) (t*=x)%=MOD;
            (x*=x)%=MOD;
            n>>=1;
        }
        modint ret(t);
        return ret;
    }
    bool operator==(const modint x) const{return a==x.a;}
    bool operator!=(const modint x) const{return a!=x.a;}
    modint operator+(const modint x) const{
        return modint(*this)+=x;
    }
    modint operator-(const modint x) const{
        return modint(*this)-=x;
    }
    modint operator*(const modint x) const{
        return modint(*this)*=x;
    }
    modint operator/(const modint x) const{
        return modint(*this)/=x;
    }
    modint operator^(const lint x) const{
        return modint(*this)^=x;
    }
    modint &operator+=(const modint &x){
        a+=x.a;
        if(a>=MOD) a-=MOD;
        return *this;
    }
    modint &operator-=(const modint &x){
        a-=x.a;
        if(a<0) a+=MOD;
        return *this;
    }
    modint &operator*=(const modint &x){
        (a*=x.a)%=MOD;
        return *this;
    }
    modint &operator/=(modint x){
        (a*=x.inv().a)%=MOD;
        return *this;
    }
    modint &operator^=(lint n){
        i64 ret=1;
        while(n){
            if(n&1) (ret*=a)%=MOD;
            (a*=a)%=MOD;
            n>>=1;
        }
        a=ret;
        return *this;
    }
    modint operator-() const{
        return modint(0)-*this;
    }
    modint &operator++(){
        return *this+=1;
    }
    modint &operator--(){
        return *this-=1;
    }
    bool operator<(const modint x) const{
        return a<x.a;
    }
};

using mint=modint<998244353>;

vector<mint> fact;
vector<mint> revfact;

void setfact(int n){
    fact.resize(n+1); revfact.resize(n+1);
    fact[0] = 1;
    rep(i, n) fact[i+1] = fact[i] * mint(i+1);

    revfact[n] = fact[n].inv();
    for(int i=n-1; i>=0; i--) revfact[i] = revfact[i+1] * mint(i+1);
}

mint getC(int n, int r){
    if(n<r) return 0;
    return fact[n] * revfact[r] * revfact[n-r];
}

string s;
set<string> S;
int n;

pii check(){
    int m = 0, f = -1;
    rep(i, n){
        (m += s[i] - 'a') %= 3;
        if(i < n-1){
            if(f < 0 && s[i] == s[i+1]) f = 0;
            else if(f < 0 && s[i] != s[i+1]) f = 1;
            else if((f == 0 && s[i] != s[i+1]) || (f == 1 && s[i] == s[i+1])) f = 2;
        }
    }
    return {m, f};
}

void dfs(string t){
    if(S.find(t) != S.end()) return;
    S.insert(t);
    rep(i, n-1)if(t[i] != t[i+1]){
        char x = t[i], y = t[i+1];
        t[i] = t[i+1] = 'a'+'b'+'c' - (t[i]+t[i+1]);
        dfs(t);
        t[i] = x; t[i+1] = y;
    }
}

int main(){
    cin >> s;
    n = s.size();
    int m, f;
    tie(m, f) = check();
    if(f == 0) printf("%d\n", 1);
    else{
        if(n <= 3){
            dfs(s);
            printf("%d\n", S.size());
        }
        else{
            mint ans = mint(3) ^ (n-1);
            if(f == 1) ++ans;
            mint dp[n][3][3];
            rep(i, n)rep(j, 3)rep(k, 3) dp[i][j][k] = 0;
            rep(j, 3) dp[0][j][j] = 1;
            rep(i, n-1)rep(j, 3)rep(k, 3)if(dp[i][j][k] != 0){
                rep(l, 3)if(l != j) dp[i+1][l][(k+l)%3] += dp[i][j][k];
            }
            rep(j, 3) ans -= dp[n-1][j][m];
            printf("%lld\n", ans.a);
        }
    }
}

Measured memory_bytes: 14596