#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using namespace atcoder;

using mint = modint998244353;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    string s; cin >> s;
    vector<mint> dp(4);
    dp[3] = 1;
    for (char c : s) {
        vector<mint> nxt(4);
        if (c != '1') {
            nxt[0] += dp[0] + dp[3];
            nxt[1] += dp[1];
            nxt[2] += dp[2] + dp[1];
            nxt[3] += dp[3];
        }
        if (c != '0') {
            nxt[0] += dp[0];
            nxt[1] += dp[1] + dp[0];
            nxt[2] += dp[2];
            nxt[3] += dp[3];
        }
        dp = nxt;
    }
    cout << dp[2].val();
}