#include <bits/stdc++.h>
#include <atcoder/all>
// https://qandori.github.io/cp-library/
using namespace std;
using namespace atcoder;
#define rep(i, l, r) for (ll i = (l); i < (r); ++i)
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pl = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvl = vector<vector<ll>>;
using vvvl = vector<vector<vector<ll>>>;
template<class T> using pq_ = priority_queue<T, vector<T>, greater<T>>;
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
// g++ a.cpp -std=c++23 -I.
// g++ -std=c++23 -I. a.cpp -o main
// g++ -std=c++23 -I. anaive.cpp -o naive
// g++ -std=c++23 -I. agene.cpp -o gene

using mint = modint998244353;

int main(){
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    ll trc=2100000;
    vector<mint> bik(trc+1);
    vector<mint> gbik(trc+1);
    bik[0]=1;
    rep(i,0,trc){
        bik[i+1]=bik[i]*(i+1);
    }
    gbik[trc]=1/bik[trc];
    rep(i,0,trc){
        gbik[trc-i-1]=gbik[trc-i]*(trc-i);
    }
    ll n;
    cin>>n;
    string s;
    cin>>s;
    ll e=0;
    ll f=0;
    rep(i,0,n){
        if(s[i]=='A'||s[i]=='B')e++;
        else f++;
    }
    cout<<(bik[n]*gbik[e]*gbik[f]).val()<<endl;
}