typedef long long ll;
typedef long double ld;

#include <bits/stdc++.h>
using namespace std;
const ll MOD = 998244353;
signed main() {
    ll n;
    std::cin >> n;
    string s;
    std::cin >> s;
    vector<vector<ll>> dp(n+1, vector<ll>(3));
    dp[0][0] = 1;
    // ULR
    for (int i = 0; i < n; i++) {
        dp[i+1][0] = dp[i][0]+dp[i][1]+dp[i][2];
        dp[i+1][1] = dp[i][0]+dp[i][1];
        dp[i+1][2] = dp[i][0]+dp[i][1]+dp[i][2];
        dp[i+1][0] %= MOD;
        dp[i+1][1] %= MOD;
        dp[i+1][2] %= MOD;
        if(s[i]=='L'){
            dp[i+1][0] = 0;
            dp[i+1][2] = 0;
        }else if(s[i]=='R'){
            dp[i+1][0] = 0;
            dp[i+1][1] = 0;
        }else if(s[i]=='U'){
            dp[i+1][2] = 0;
            dp[i+1][1] = 0;
        }
    }
    std::cout << (dp[n][0]+dp[n][1]+dp[n][2])%MOD << std::endl;
};