#include<bits/stdc++.h>
using namespace std;
typedef unsigned long long int ull;
typedef long long int ll;
typedef pair<ll,ll> pll;
typedef long double D;
typedef complex<D> P;
#define F first
#define S second
const ll E=1e18+7;
const ll MOD=998244353;//1000000007;

template<typename T,typename U>istream & operator >> (istream &i,pair<T,U> &A){i>>A.F>>A.S; return i;}
template<typename T>istream & operator >> (istream &i,vector<T> &A){for(auto &I:A){i>>I;} return i;}
template<typename T,typename U>ostream & operator << (ostream &o,const pair<T,U> &A){o<<A.F<<" "<<A.S; return o;}
template<typename T>ostream & operator << (ostream &o,const vector<T> &A){ll i=A.size(); for(auto &I:A){o<<I<<(--i?" ":"");} return o;}
template<typename T>vector<T> & cset(vector<T> &A,T e=T()){for(auto &I:A){I=e;} return A;}

template<long long int mod=1000000007>
struct Mod_Int{
    typedef long long int ll;
    typedef pair<ll,ll> pll;
    typedef Mod_Int<mod> M;
    ll a;
    
    ll mod_pow(ll a,ll x){
        a%=mod;
        ll ans=1;
        for(int i=0;i<63;i++){
            if(x>>i&1){ans*=a; ans%=mod;}
            a*=a;
            a%=mod;
        }
        return ans;
    }
    
    pll Ex_gcd(ll a,ll b){
        if(b==0){return {1,0};}
        pll ret=Ex_gcd(b,a%b);
        ret.F-=a/b*ret.S;
        return {ret.S,ret.F};
    }
    
    ll prime_R(ll a){
        return mod_pow(a,mod-2);
    }
    
    ll R(ll a){
        ll ret=Ex_gcd(a,mod).F;
        ret%=mod;
        if(ret<0){ret+=mod;}
        return ret;
    }
    
    Mod_Int(ll A=1):a(A){
        a%=mod;
        if(a<0){a+=mod;}
    }
    
    Mod_Int(const M &b):a(b.a){}
    
    M & operator += (const M &b){
        a+=b.a;
        if(a>=mod){a-=mod;}
        return *this;
    }
    
    M operator + (const M &b) const {
        M c=*this;
        return c+=b;
    }
    
    M & operator -= (const M &b){
        a-=b.a;
        if(a<0){a+=mod;}
        return *this;
    }
    
    M operator - (const M &b) const {
        M c=*this;
        return c-=b;
    }
    
    M & operator *= (const M &b){
        (a*=b.a)%=mod;
        return *this;
    }
    
    M operator * (const M &b) const {
        M c=*this;
        return c*=b;
    }
    
    M & operator /= (const M &b){
        (a*=R(b.a))%=mod;
        return *this;
    }
    
    M operator / (const M &b) const {
        M c=*this;
        return c/=b;
    }
    
    M & mod_pow_equal(ll x){
        ll ans=1;
        while(x>0){
            if(x&1){ans*=a; ans%=mod;}
            a*=a;
            a%=mod;
            x>>=1;
        }
        a=ans;
        return *this;
    }
    
    M mod_pow(ll x){
        M c(a);
        return c.mod_pow_equal(x);
    }
    
    bool operator == (const M &b) const {return a==b.a;}
    
    bool operator != (const M &b) const {return a!=b.a;}
    
    bool operator <= (const M &b) const {return a<=b.a;}
    
    bool operator < (const M &b) const {return a<b.a;}
    
    bool operator > (const M &b) const {return a>b.a;}
    
    bool operator >= (const M &b) const {return a>=b.a;}
    
    M & operator = (const M &b){
        a=b.a;
        return *this;
    }
    
    M & operator = (const ll &b){
        (a=b)%=mod;
        if(a<0){a+=mod;}
        return *this;
    }
};

template<long long MOD>istream & operator >> (istream &i,Mod_Int<MOD> &A){ll a; cin>>a; A=Mod_Int<MOD>(a); return i;}
template<long long MOD>ostream & operator << (ostream &i,const Mod_Int<MOD> &A){i<<A.a; return i;}


typedef Mod_Int<MOD> Int;


int main(){
  ll N;
  cin>>N;
  string s;
  cin>>s;
  for(auto &I:s){
    if(I=='R'){I=0;}
    else if(I=='G'){I=1;}
    else{I=2;}
  }
  vector<vector<ll>> cnt(3,vector<ll>(4,0));
  Int ans=1;
  for(int i=0;i<3*N;i++){
    int wd=s[i];
    int jb=-1,kb=-1;
    for(int j=0;j<3;j++){
      if(j==wd){continue;}
      for(int k=j+1;k<3;k++){
        if(k==wd){continue;}
        if(cnt[j][k]==0){continue;}
        jb=j;
        kb=k;
      }
    }
    if(jb!=-1){
      ans*=cnt[jb][kb];
      cnt[jb][kb]--;
    }
    else{
      for(int j=0;j<3;j++){
        if(j==wd){continue;}
        if(cnt[j][3]!=0){jb=j;}
      }
      if(jb!=-1){
        if(jb<wd){
          cnt[jb][wd]++;
          //ans*=cnt[jb][wd];
          ans*=cnt[jb][3];
          cnt[jb][3]--;
        }
        else{
          cnt[wd][jb]++;
          //ans*=cnt[wd][jb];
          ans*=cnt[jb][3];
          cnt[jb][3]--;
        }
      }
      else{
        cnt[wd][3]++;
      }
    }
    //cout<<i<<" "<<ans<<endl;
  }

  for(int i=1;i<=N;i++){ans*=i;}
  cout<<ans<<endl;
  

  return 0;
}


Measured memory_bytes: 900