S = list(input())
N = len(S)
dp0 = [0] * (N + 1)
dp1 = [0] * (N + 1)
dp2 = [0] * (N + 1)
mod = 998244353
cnt = 1
for i in range(N):
    if S[i] == "0" or S[i] == "?":
        dp0[i + 1] += dp0[i]
        dp1[i + 1] += dp1[i]
        dp2[i + 1] += dp2[i]
        dp0[i + 1] += cnt
        dp2[i + 1] += dp1[i]
    if S[i] == "1" or S[i] == "?":
        dp0[i + 1] += dp0[i]
        dp1[i + 1] += dp1[i]
        dp2[i + 1] += dp2[i]
        dp1[i + 1] += dp0[i]
    if S[i] == "?":
        cnt *= 2
        cnt %= mod
    dp0[i + 1] %= mod
    dp1[i + 1] %= mod
    dp2[i + 1] %= mod

print(dp2[-1])