mod = 998244353
N = 5 * 10**5 + 5
fact = [1]*(N+1)
factinv = [1]*(N+1)

for i in range(2, N+1):
	fact[i] = fact[i-1] * i % mod

factinv[-1] = pow(fact[-1], mod-2, mod)
for i in range(N-1, 1, -1):
	factinv[i] = factinv[i+1] * (i+1) % mod

def cmb(a, b):
	if (a < b) or (b < 0):
		return 0
	return fact[a] * factinv[b] % mod * factinv[a-b] % mod

n=int(input())
s = input()
ans=0
if s == "("*(n//2)+")"*(n//2):
	ans=cmb(n,n//2)
else:
	assert s == "()"*(n//2)
	ans = pow(2,n//2,mod)
print(ans)