#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define ll long long
#define db long double
#define ii pair<int,int>
#define vi vector<int>
#define fi first
#define se second
#define sz(a) (int)(a).size()
#define all(a) (a).begin(),(a).end()
#define pb push_back
#define mp make_pair
#define FN(i, n) for (int i = 0; i < (int)(n); ++i)
#define FEN(i,n) for (int i = 1;i <= (int)(n); ++i)
#define rep(i,a,b) for(int i=a;i<b;i++)
#define repv(i,a,b) for(int i=b-1;i>=a;i--)
#define SET(A, val) memset(A, val, sizeof(A))
typedef tree<int ,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>ordered_set ;
// order_of_key (val): returns the no. of values less than val
// find_by_order (k): returns the kth largest element.(0-based)
#define TRACE
#ifdef TRACE
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
  cerr << name << " : " << arg1 << std::endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
  const char* comma = strchr(names + 1, ','); cerr.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...);
}
#else
#define trace(...)
#endif
const int mod=998244353,N=100005;
int add(int x,int y)
{
  x+=y;
  if(x>=mod) x-=mod;
  if(x<0) x+=mod;
  return x;
}
int mult(int x,int y)
{
  ll tmp=(ll)x*y;
  if(tmp>=mod) tmp%=mod;
  return tmp;
}
//R,G,B,RG,RB,BG
map<vi,int> dp[3*N];
string s;
int fun(vi v,int ind)
{
  if(ind==sz(s)) return 1;
  if(dp[ind].count(v)) return dp[ind][v];
  int ans=0,id;
  if(s[ind]=='R') id=0;
  else if(s[ind]=='G') id=1;
  else id=2;
  int nxt1=(id+1),nxt2=(id+2);
  nxt1%=3; nxt2%=3;
  if(v[5-id])//2 are there
    {
      vi tmp(v);
      tmp[5-id]--;
      ans=mult(v[5-id],fun(tmp,ind+1));
    }
  else if(!v[nxt1] && !v[nxt2])//no single is there to join
    {
      vi tmp(v);
      tmp[id]++;
      ans=fun(tmp,ind+1);
    }
  else//join with one of the singles
    {
      if(s[ind]=='R')
	{
	  vi tmp(v);
	  //RG
	  if(tmp[nxt1])
	    {
	      tmp[nxt1]--; tmp[3]++;
	      ans=add(ans,mult(v[nxt1],fun(tmp,ind+1)));
	      tmp[nxt1]++; tmp[3]--;
	    }
	  //RB
	  if(tmp[nxt2])
	    {
	      tmp[nxt2]--; tmp[4]++;
	      ans=add(ans,mult(v[nxt2],fun(tmp,ind+1)));
	      tmp[nxt2]++; tmp[4]--;
	    }
	}
      else if(s[ind]=='G')
	{
	  vi tmp(v);
	  //GB
	  if(tmp[nxt1])
	    {
	      tmp[nxt1]--; tmp[5]++;
	      ans=add(ans,mult(v[nxt1],fun(tmp,ind+1)));
	      tmp[nxt1]++; tmp[5]--;
	    }
	  //RG
	  if(tmp[nxt2])
	    {
	      tmp[nxt2]--; tmp[3]++;
	      ans=add(ans,mult(v[nxt2],fun(tmp,ind+1)));
	      tmp[nxt2]++; tmp[3]--;
	    }
	}
      else
	{
	  vi tmp(v);
	  //RB
	  if(tmp[nxt1])
	    {
	      tmp[nxt1]--; tmp[4]++;
	      ans=add(ans,mult(v[nxt1],fun(tmp,ind+1)));
	      tmp[nxt1]++; tmp[4]--;
	    }
	  //BG
	  if(tmp[nxt2])
	    {
	      tmp[nxt2]--; tmp[5]++;
	      ans=add(ans,mult(v[nxt2],fun(tmp,ind+1)));
	      tmp[nxt2]++; tmp[5]--;
	    }
	}
    }
  return dp[ind][v]=ans;
}
int main()
{
  std::ios::sync_with_stdio(false);
  cin.tie(NULL) ; cout.tie(NULL) ;
  int n;
  cin>>n;
  cin>>s;
  vi v;
  v.resize(6,0);
  int ans=fun(v,0);
  rep(i,1,n+1) ans=mult(ans,i);
  cout<<ans<<endl;
  return 0 ;
}


Measured memory_bytes: 108308