from itertools import accumulate


MOD = 998244353

S = input()
INV2 = pow(2, MOD - 2, MOD)
a = []
c = 0
for i in range(len(S)):
    if S[i] == '0':
        a.append(1)
    elif S[i] == '?':
        a.append(INV2)
        c += 1
    else:
        a.append(0)

acl = [0]
now = 0
for i in a:
    now += i
    now %= MOD
    acl.append(now)

a.reverse()
acr = [0]
now = 0
for i in a:
    now += i
    now %= MOD
    acr.append(now)
acr.reverse()
a.reverse()

ans = 0
for i in range(len(a)):
    ans += (1 - a[i]) * acl[i] * acr[i + 1]
    ans %= MOD

print((ans * pow(2, c, MOD)) % MOD)