#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using mint=atcoder::modint998244353;

int main(){
    int n;cin>>n;
    string s;cin>>s;
    mint lf=1,rf=0;
    for(int i=0;i<n;i++){
        if(s[i]=='R'){
            rf+=lf;
            lf=0;
        }else if(s[i]=='L'){
            rf=0;
        }else if(s[i]=='U'){
            lf+=rf;
            rf=0;
        }else{
            rf+=lf;
            lf+=rf;
        }
    }
    cout<<(lf+rf).val()<<"\n";
}