mod=998244353

s=input()
n=len(s)

dp=[0,0]
ans=0
inv2=pow(2,mod-2,mod)
cnt=0
for i in s:
  ndp=[0,0]
  if i=='0':
    ans+=dp[1]
    ndp[0]=dp[0]+1
    ndp[1]=dp[1]
  if i=='1':
    ndp[0]=dp[0]
    ndp[1]=dp[0]+dp[1]
  if i=='?':
    cnt+=1
    ans+=dp[1]*inv2
    ndp[1]=dp[1]+dp[0]*inv2
    ndp[0]=dp[0]+inv2
  dp=[i%mod for i in ndp]
  

print(ans*pow(2,cnt,mod)%mod)