#include<bits/stdc++.h>
#define ls rt<<1
#define rs rt<<1|1
#define mid ((l+r)>>1)
using namespace std;
typedef vector<int> poly;
const int mod=998244353;
const int N=1e5+5;

poly t[N<<2][2][2];
int ae[N][2],av[N][2];
int f[N<<3],g[N<<3],rev[N<<3];
char s[N];
int n,len,bit,inv3=(mod+1)/3;

int mul(int a,int b){return 1ll*a*b%mod;}
void inc(int&a,int b){a=a>=mod-b?a-mod+b:a+b;}
int ksm(int a,int b){
    int res=1;
    while(b) {
        if(b&1) res=mul(res,a);
        a=mul(a,a),b>>=1;
    }
    return res;
}
void ntt(int *f,int op) {
    for(int i=0;i<len;++i) if(i<rev[i]) swap(f[i],f[rev[i]]);
    for(int i=2;i<=len;i<<=1) {
        int base=ksm(op==1?3:inv3,(mod-1)/i);
        for(int j=0,p=i>>1;j<len;j+=i)
            for(int k=0,pw=1,x,y;k<p;++k,pw=mul(pw,base)) 
                x=f[j+k],y=mul(f[j+k+p],pw),
                f[j+k]=(x+y)%mod,f[j+k+p]=(x-y+mod)%mod;
    }
    if(op==-1)
        for(int i=0,inv=ksm(len,mod-2);i<len;++i)
            f[i]=mul(f[i],inv);
}

poly operator*(const poly&a,const poly&b) {
    if(a.empty()||b.empty()) return {};
    int n=a.size(),m=b.size();
    len=1,bit=0;
    while(len<n+m-1) len<<=1,++bit;

    for(int i=0;i<len;++i) 
        rev[i]=(rev[i>>1]>>1)|((i&1)<<bit-1),
        f[i]=g[i]=0;
    for(int i=0;i<n;++i) f[i]=a[i];
    for(int i=0;i<m;++i) g[i]=b[i];


    ntt(f,1),ntt(g,1);
    for(int i=0;i<len;++i) f[i]=mul(f[i],g[i]);
    ntt(f,-1);

    poly c(n+m-1);
    for(int i=0;i<n+m-1;++i) c[i]=f[i];
    return c;
}
poly operator+(const poly&a,const poly&b) {
    if(a.empty()) return b;
    if(b.empty()) return a;
    int n=max(a.size(),b.size());
    poly c(n);
    for(int i=0;i<n;++i) {
        if(i<(int)a.size()) inc(c[i],a[i]);
        if(i<(int)b.size()) inc(c[i],b[i]);
    }
    return c;
}

void solve(int l,int r,int rt) {
    if(l==r) {
        for(int e=0;e<2;++e) if(ae[l][e])
            t[rt][e][e]={0,av[l][0]+av[l][1]},
            t[rt][e][e^1]={e==0&&av[l][0],av[l][1],e==1&&av[l][0]};
        return ;
    } 
    solve(l,mid,ls),solve(mid+1,r,rs);
    for(int i=0;i<2;++i) for(int k=0;k<2;++k) for(int j=0;j<2;++j)
        t[rt][i][j]=t[rt][i][j]+t[ls][i][k]*t[rs][k][j];
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0),cout.tie(0);

    cin>>n>>(s+1);
    for(int i=1;i<=n;++i) {
        ae[i][0]=(s[2*i-1]!='Y');
        ae[i][1]=(s[2*i-1]!='P');
        av[i][0]=(s[2*i]!='R');
        av[i][1]=(s[2*i]!='B');
    }

    solve(1,n,1);

    poly ans=t[1][0][0]+t[1][1][1];
    if(ans.size()>n) cout<<ans[n]<<"\n";
    else cout<<"0\n";
    return 0;
}