MOD = 998244353
N = int(input())
A = input().strip()
if A=="0"*N or A=="1"*N:
    print(1)
else:
    B = []
    cnt = 1
    for i in range(N-1):
        if A[i]=="1" and A[i+1]=="0":
            B.append(cnt)
            cnt = 1
        else:
            cnt += 1
    if A[0]=="1":
        if len(B)==0:
            B.append(0)
        else:
            B[0] = 0
    if A[-1]=="0":
        B.append(0)
    else:
        B.append(cnt)
    ans = 1
    for b in B:
        ans = (ans*(b+1))%MOD
    print(ans)