#include <bits/stdc++.h>
using namespace std;
const int N = 5e5 + 10, mod = 998244353;
int f[N][2][2];
int main() {
    int t = 1;
    // cin >> t;
    while (t--) {
        string s;
        cin >> s;
        memset(f, 0, sizeof f);
        if (s[0] == '0') {
            f[0][0][0] = 1;
        }
        if (s[0] == '1') {
            f[0][1][0] = 1;
        }
        if (s[0] == '?') {
            f[0][0][0] = 1;
            f[0][1][0] = 1;
        }
        for (int i = 1; i < s.size(); i++) {
            if (s[i] == '0') {
                f[i][0][0] = (f[i - 1][0][1] + f[i - 1][1][0]) % mod;
                f[i][0][1] = (f[i - 1][0][0] + f[i - 1][1][1]) % mod;
            }
            if (s[i] == '1') {
                f[i][1][0] = (f[i - 1][0][0] + f[i - 1][1][1]) % mod;
                f[i][1][1] = (f[i - 1][0][1] + f[i - 1][1][0]) % mod;
            }
            if (s[i] == '?') {
                f[i][0][0] = (f[i - 1][0][1] + f[i - 1][1][0]) % mod;
                f[i][0][1] = (f[i - 1][0][0] + f[i - 1][1][1]) % mod;
                f[i][1][0] = (f[i - 1][0][0] + f[i - 1][1][1]) % mod;
                f[i][1][1] = (f[i - 1][0][1] + f[i - 1][1][0]) % mod;
            }
        }
        cout << (f[s.size() - 1][1][0] + f[s.size() - 1][0][0]) % mod << '\n';
    }
    return 0;
}