N=int(input())
S=input()
mod=998244353;n=7*10**5
inv_t=[0]+[1]
for i in range(2,n):
  inv_t+=[inv_t[mod%i]*(mod-int(mod/i))%mod]

kai=[1,1]
rev_kai=[1,inv_t[1]]
for i in range(2,n):
  kai.append(kai[-1]*i%mod)
  rev_kai.append(rev_kai[-1]*inv_t[i]%mod)

def cmb(n,r):
  return kai[n]*rev_kai[r]*rev_kai[n-r]%mod

def prm(n,r):
  return kai[n]*rev_kai[n-r]%mod

A='('*(N//2)+(')')*(N//2)

if A==S:
  ans=0
  for i in range(N//2+1):
    c=cmb(N//2,i)
    ans+=c*c%mod 
    ans%=mod
  print(ans)
else:
  c=N//2
  print(pow(2,c,mod))