# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')
from collections import defaultdict as dd
S = input
R = range
P = print
def I(): return int(S())
def M(): return map(int, S().split())
def L(): return list(M())
def O(): return list(map(int, open(0).read().split()))
def yn(b): print("Yes" if b else "No")
biga = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
smaa = "abcdefghijklmnopqrstuvwxyz"
ctoi = lambda c: ord(c) - ord('a')
itoc = lambda i: chr(ord('a') + i)
inf = 10 ** 18
mod = 998244353
def acc(a):
	b = [0]
	for i in a:
		b.append(b[-1] + i)
	return b

n=I()
s=S()
dp=[0,0,1] # L,R,U
for i in s:
	if i == 'L':
		dp = [(dp[0] + dp[2]) % mod, 0, 0]
	elif i == 'R':
		dp = [0, sum(dp) % mod, 0, 0]
	elif i == 'U':
		dp = [0, 0, sum(dp) % mod]
	else:
		dp = [(dp[0] + dp[2]) % mod, sum(dp) % mod, sum(dp) % mod]
P(sum(dp) % mod)