#include<stdio.h>
char s[200005];
long long int dp[200005][3];
int main()
{
	long long int n;
	scanf("%lld", &n);
	scanf("%s", s);
	long long int i;
	const long long int p = 998244353;
	dp[0][0] = dp[0][1] = 0;
	dp[0][2] = 1;
	for (i = 0; i < n; i++)
	{
		dp[i + 1][0] = (dp[i][0] + dp[i][2]) % p;
		dp[i + 1][1] = (dp[i][0] + dp[i][1] + dp[i][2]) % p;
		dp[i + 1][2] = dp[i + 1][1];
		if (s[i] == 'L')
			dp[i + 1][1] = dp[i + 1][2] = 0;
		else if (s[i] == 'R')
			dp[i + 1][0] = dp[i + 1][2] = 0;
		else if (s[i] == 'U')
			dp[i + 1][0] = dp[i + 1][1] = 0;
	}
	printf("%lld\n", (dp[n][0] + dp[n][1] + dp[n][2]) % p);
	return 0;
}