#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;

constexpr ll mod = 998244353;

void add(int &x,int y) {
    x += y;
    if(x >= mod) x -= mod;
}

// 1-indexed
struct BIT{
    int n;
    vector<int> bit;
    BIT() {};
    BIT(int n) : n(n),bit(n+1) {}
    int sum(int i){
        int res = 0;
        for(;i>0;i-=(i&-i)){
            res += bit[i];
            if(res >= mod) res -= mod;
//            add(res,bit[i]);
        }
        return res;
    }
    void add(int i,int a){
        if(i == 0) return;
        for(;i<=n;i+=(i&-i)){
            bit[i] += a;
            if(bit[i] >= mod) bit[i] -= mod;
//            add(bit[i],a);
        }
    }
};

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    string s; cin >> s;
    int n = s.size();
    vector<vector<int>> sum(3,vector<int>(n+1));
    for (int i = 0; i < n; ++i) {
        int c = 0;
        if(s[i] == 'I') c = 0;
        else if(s[i] == 'C') c = 1;
        else c = 2;
        for (int j = 0; j < 3; ++j) {
            sum[j][i+1] += sum[j][i];
        }
        sum[c][i+1]++;
    }
    map<int,vector<int>> mp[3];
    for (int i = 0; i <=n ; ++i) {
        for (int j = 0; j < 3; ++j) {
            int jj = (j+1)%3;
            int jjj = (j+2)%3;
            int key = sum[jj][i] - sum[j][i];
            int val = sum[jjj][i] - sum[jj][i];
            mp[j][key].push_back(val);
        }
    }
    for(int i=0;i<3;i++){
        for(auto &p:mp[i]){
            sort(p.second.begin(), p.second.end());
            p.second.erase(unique(p.second.begin(), p.second.end()), p.second.end());
//            reverse(p.second.begin(), p.second.end());
        }
    }
    vector<int> dp(n+1);
    dp[0] = 1;
    BIT bit[3];
    for (int i = 0; i < 3; ++i) {
        bit[i] = BIT(n+1);
    }
    map<pair<int,int>,int> id[3];
    map<pair<int,int>,pair<int,int>> memo[3];
    for (int i = 0; i < 3; ++i) {
        int num = 1;
        for(auto &p:mp[i]){
            int be = num-1;
//            int ed = num+p.second.size()-1;
            for (int j = 0; j < p.second.size(); ++j) {
//                cout << i << " " << p.first << " " << p.second[j] << " " << num << endl;
                id[i][{p.first, p.second[j]}] = num;
                memo[i][{p.first,p.second[j]}] = {be,num-1};
                num++;
            }
        }
    }
    auto update = [&](int i)->void{
        for (int j = 0; j < 3; ++j) {
            int jj = (j+1)%3;
            int jjj = (j+2)%3;
            int key = sum[jj][i] - sum[j][i];
            int val = sum[jjj][i] - sum[jj][i];
            int idx = id[j][{key,val}];
//            cout << i << endl;
//            cout << idx << " " << dp[i] << endl;
            bit[j].add(idx, dp[i]);
        }
    };
    update(0);
    for (int i = 1; i <= n; ++i) {
        for (int j = 0; j < 3; ++j) {
            int jj = (j+1)%3;
            int jjj = (j+2)%3;
            int key = sum[jj][i] - sum[j][i];
            int val = sum[jjj][i] - sum[jj][i];
            auto p = memo[j][{key,val}];
//            cout << i << " " << j << " " << p.first << " " << p.second << endl;
            add(dp[i], bit[j].sum(p.second));
            add(dp[i], mod-bit[j].sum((p.first)));
        }
        update(i);
//        cout << dp[i] << endl;;
    }
    cout << dp[n] << endl;
}