import sys

inputs = sys.stdin.readline
MOD = 998244353

"""再帰関数のときセット
sys.setrecursionlimit(10**7)
import pypyjit
pypyjit.set_param('max_unroll_recursion=-1')
"""


def main():
    S = input()
    total_q = S.count('?')
    base_cnt = pow(2, total_q, MOD)
    half_cnt = pow(2, total_q - 1, MOD)
    rev2 = pow(2, MOD - 2, MOD)

    cnt_0 = 0
    cnt_01 = 0
    ans = 0
    for s in S:
        if s == '0':
            ans = (ans + cnt_01) % MOD
            cnt_0 = (cnt_0 + base_cnt) % MOD
        elif s == '1':
            cnt_01 = (cnt_01 + cnt_0) % MOD
        else:
            ans = (ans + cnt_01 * rev2 % MOD) % MOD
            cnt_01 = (cnt_01 + cnt_0 * rev2 % MOD) % MOD
            cnt_0 = (cnt_0 + half_cnt) % MOD

    print(ans)


if __name__ == '__main__':
    main()