#include <iostream>
#include <string>
#include <cmath>
#include<algorithm>
#include<stack>
#include<queue>
#include<map>
#include<set>
#include<iomanip>
#define _USE_MATH_DEFINES
#include <math.h>
#include <functional>
#include<complex>
using namespace std;

#define rep(i,x) for(ll i=0;i<x;i++)
#define repn(i,x) for(ll i=1;i<=x;i++)

typedef long long ll;
const ll INF = 1e17;
const ll MOD = 998244353;
const ll MAX = 4000001;
const long double eps = 1E-14;

ll max(ll a, ll b) {
	if (a > b) { return a; }
	return b;
}

ll min(ll a, ll b) {
	if (a > b) { return b; }
	return a;
}

ll gcd(ll a, ll b) {
	if (b == 0) { return a; }
	if (a < b) { return gcd(b, a); }
	return gcd(b, a % b);
}

ll lcm(ll a, ll b) {
	return a / gcd(a, b) * b;
}

struct edge {
	ll ind;
	ll fr;
	ll to;
	ll d;
};

class mint {
	long long x;
public:
	mint(long long 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 {
		mint res(*this);
		return res += a;
	}
	mint operator-(const mint& a) const {
		mint res(*this);
		return res -= a;
	}
	mint operator*(const mint& a) const {
		mint res(*this);
		return res *= 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 {
		mint res(*this);
		return res /= a;
	}

	friend ostream& operator<<(ostream& os, const mint& m) {
		os << m.x;
		return os;
	}
};

mint pw(mint a, ll b) {
	if (b == 0) { return 1; }
	mint ret = pw(a, b >> 1);
	ret *= ret;
	if (b & 1) { ret *= a; }
	return ret;
}

typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<vector<vector<ll>>> vvvll;

typedef vector<mint> vmint;
typedef vector<vector<mint>> vvmint;
typedef vector<vector<vector<mint>>> vvvmint;

//////////////////////////////////////

set<vll> st;

void dfs(vll a) {
	st.insert(a);
	rep(i, a.size() - 1) {
		if (a[i] == a[i + 1]) { continue; }

		vll b = a;
		ll x = 3 - (a[i] + a[i + 1]);
		b[i] = x;
		b[i + 1] = x;

		if (st.count(b)) { continue; }
		dfs(b);
	}
}

int main() {
	string S;
	cin >> S;

	ll N = S.size();

	if (N < 8) {
		vll a(N);
		rep(i, N)a[i] = S[i] - 'a';
		dfs(a);
		cout << st.size() << endl;

		return 0;
	}

	bool same = 1;
	bool diff = 1;
	rep(i, N - 1) {
		if (S[i] != S[i + 1]) {same = 0;}
		else { diff = 0; }
	}

	mint all = pw(3,N - 1);
	mint ans;

	vvvmint dp(N + 1, vvmint(3, vmint(3, 0)));
	rep(j, 3)dp[1][j][j] = 1;
	for (ll i = 2; i <= N; i++) {
		rep(j, 3)rep(k, 3) {
			rep(l, 3)rep(m, 3) {
				if ((l + k) % 3 == j && m != k) {
					dp[i][j][k] += dp[i - 1][l][m];
				}
			}
		}
	}

	ll c = 0;
	rep(i, N) c += S[i] - 'a';
	c %= 3;
	mint d = 0;
	rep(j, 3)d += dp[N][c][j];

	//cout << d << endl;
	
	if (N >= 4) {

		if (same) { ans = 1; }
		else if (diff) { ans = all - d + 1; }
		else { ans = all - d; }
	}
	else {
		if (same) { ans = 1; }
		else if (diff) {
			if (S[0] == S[2]) { ans = 7; }
			else { ans = 3; }
		}
		else { ans = 6; }
	}

	cout << ans << endl;
}


Measured memory_bytes: 42388