#include <bits/stdc++.h>
using namespace std;

#define fs first
#define sc second
#define pb emplace_back
#define mp make_pair
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()

const int32_t inf = 1001001001;
const int64_t infll = 1001001001001001001ll;
const int dx[] = {0, -1, 1, 0, -1, 1, -1, 1}, dy[] = {-1, 0, 0, 1, -1, -1, 1, 1};

template <typename T> using vector2d = vector<vector<T>>;

// clang-format off
template <typename T> void sort(vector<T> &v) { sort(all(v)); }
// ostream &operator<<(ostream &os, __int128_t value) { if (ostream::sentry(os)) { __uint128_t tmp = value < 0 ? -value : value; char buffer[64]; char *d = end(buffer); do { --d; *d = "0123456789"[tmp % 10]; tmp /= 10; } while (tmp != 0); if (value < 0) { --d; *d = '-'; } int len = end(buffer) - d; if (os.rdbuf()->sputn(d, len) != len) { os.setstate(ios_base::badbit); }} return os; }
// istream &operator>>(istream &is, __int128_t &value) { string in; is >> in; value = 0; for (const char &c : in) { if ('0' <= c && c <= '9') value = 10 * value + (c - '0'); } if (in[0] == '-') value *= -1; return is; }
// ostream &operator<<(ostream &os, __uint128_t value) { if (ostream::sentry(os)) { char buffer[64]; char *d = end(buffer); do { --d; *d = "0123456789"[value % 10]; value /= 10; } while (value != 0); int len = end(buffer) - d; if (os.rdbuf()->sputn(d, len) != len) { os.setstate(ios_base::badbit); }} return os; }
// istream &operator>>(istream &is, __uint128_t &value) { string in; is >> in; value = 0; for (const char &c : in) { if ('0' <= c && c <= '9') value = 10 * value + (c - '0'); } return is; }
template <typename T> ostream &operator<<(ostream &os, vector<T> &v) { os << v[0]; for (int i = 1; i < v.size(); ++i) os << " " << v[i]; return os; }
template <typename T> istream &operator>>(istream &is, vector<T> &v) { for (T &in : v) is >> in; return is; }
template <typename T1, typename T2> ostream &operator<<(ostream &os, pair<T1, T2> p) { os << p.fs << " " << p.sc; return os; }
template <typename T1, typename T2> istream &operator>>(istream &is, pair<T1, T2> &p) { is >> p.fs >> p.sc; return is; }

struct IoSetup { IoSetup(){ cin.tie(0); ios::sync_with_stdio(0); cout << fixed << setprecision(10); cerr << fixed << setprecision(10); } } iosetup;

inline int64_t in() { int64_t x = 0; cin >> x; return x; }
template <typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template <typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }
// clang-format on

const int mod = 998244353;
int64_t dp[202020][3][2][4];

string s;

char not_used(char a, char b) {
  if (a != 'a' && b != 'a') return 'a';
  if (a != 'b' && b != 'b') return 'b';
  if (a != 'c' && b != 'c') return 'c';
}

int po(string t) {
  sort(all(t));
  t.erase(unique(all(t)), t.end());
  return t.size() == 1;
}

int latte() {
  set<string> st;
  queue<string> q;
  q.push(s);

  while (!q.empty()) {
    string t = q.front();
    q.pop();

    if (st.count(t)) continue;
    st.insert(t);

    for (int i = 0; i + 1 < t.size(); ++i) {
      if (t[i] != t[i + 1]) {
        string po = t;
        po[i] = po[i + 1] = not_used(t[i], t[i + 1]);
        q.push(po);
      }
    }
  }

  return st.size();
}

int64_t dfs(int idx, int sum, bool f = false, int pre = 3) {
  if (idx == s.size()) {
    return sum == 0 && f;
  }

  int64_t &res = dp[idx][sum][f][pre];
  if (~res) return res;

  res = 0;
  for (int i = 0; i < 3; ++i) {
    (res += dfs(idx + 1, (sum + i) % 3, f || i == pre, i)) %= mod;
  }

  return res;
}

signed main(int argc, char *argv[]) {
  cin >> s;

  if (po(s)) {
    cout << 1 << endl;
    return 0;
  }

  if (s.size() < 5) {
    cout << latte() << endl;
  } else {
    bool di = true;
    for (int i = 0; i + 1 < s.size(); ++i) {
      if (s[i] == s[i + 1]) di = false;
    }

    int cnt = 0;
    for (int i = 0; i < s.size(); ++i) {
      (cnt -= s[i] - 'a' - 3) %= 3;
    }

    memset(dp, -1, sizeof(dp));
    int ans = dfs(0, cnt);
    if (di) (ans += 1) %= mod;

    cout << ans << endl;
  }
}


Measured memory_bytes: 54096