# include <bits/stdc++.h>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
const double PI = acos(-1);
template<class T>constexpr T INF() { return ::std::numeric_limits<T>::max(); }
template<class T>constexpr T HINF() { return INF<T>() / 2; }
template <typename T_char>T_char TL(T_char cX) { return tolower(cX); }
template <typename T_char>T_char TU(T_char cX) { return toupper(cX); }
template<class T> bool chmin(T& a,T b) { if(a > b){a = b; return true;} return false; }
template<class T> bool chmax(T& a,T b) { if(a < b){a = b; return true;} return false; }
template<class T> bool is_sqare(T a) { if(floor(sqrt(a)) * floor(sqrt(a)) == a){ return true; }return false; }
int popcnt(unsigned long long n) { int cnt = 0; for (int i = 0; i < 64; i++)if ((n >> i) & 1)cnt++; return cnt; }
int d_sum(LL n) { int ret = 0; while (n > 0) { ret += n % 10; n /= 10; }return ret; }
int d_cnt(LL n) { int ret = 0; while (n > 0) { ret++; n /= 10; }return ret; }
template<class T> using dijk = priority_queue<T, vector<T>, greater<T>>;
# define ALL(qpqpq)           (qpqpq).begin(),(qpqpq).end()
# define UNIQUE(wpwpw)        sort(ALL((wpwpw)));(wpwpw).erase(unique(ALL((wpwpw))),(wpwpw).end())
# define LOWER(epepe)         transform(ALL((epepe)),(epepe).begin(),TL<char>)
# define UPPER(rprpr)         transform(ALL((rprpr)),(rprpr).begin(),TU<char>)
# define REP(i,upupu)         for(LL i = 0, i##_len = (upupu);(i) < (i##_len);(i)++)
# define REPS(i,opopo)        for(LL i = 1, i##_len = (opopo);(i) <= (i##_len);(i)++)
# define len(x)                ((int)(x).size())
# define BIT(n)               (1LL << (n))

#ifdef LOCAL
#  include "_debug_print.hpp"
#  define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define debug(...) (static_cast<void>(0))
#endif

struct INIT{
    INIT(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(0);
        cout << fixed << setprecision(20);
    }
}INIT;

template <std::uint_fast64_t Modulus> class modint {
	using u64 = std::uint_fast64_t;
public:
	u64 a;
	constexpr modint(const u64 x = 0) noexcept : a(x % Modulus) {}
	constexpr u64 &value() noexcept { return a; }
	constexpr const u64 &value() const noexcept { return a; }
	constexpr modint operator+(const modint rhs) const noexcept {
		return modint(*this) += rhs;
	}
	constexpr modint operator-(const modint rhs) const noexcept {
		return modint(*this) -= rhs;
	}
	constexpr modint operator*(const modint rhs) const noexcept {
    	return modint(*this) *= rhs;
	}
	constexpr modint operator/(const modint rhs) const noexcept {
		return modint(*this) /= rhs;
	}
	constexpr modint &operator+=(const modint rhs) noexcept {
		a += rhs.a;
		if (a >= Modulus) {
			a -= Modulus;
		}
    	return *this;
	}
	constexpr modint &operator-=(const modint rhs) noexcept {
		if (a < rhs.a) {
			a += Modulus;
		}
		a -= rhs.a;
		return *this;
	}
	constexpr modint &operator*=(const modint rhs) noexcept {
    	a = a * rhs.a % Modulus;
    	return *this;
	}
	constexpr modint &operator/=(modint rhs) noexcept {
		u64 exp = Modulus - 2;
		while (exp) {
			if (exp % 2) {
				*this *= rhs;
			}
			rhs *= rhs;
			exp /= 2;
		}
    	return *this;
	}
};

using mint = modint<998244353>;

void solve(){
    string s;
    cin >> s;
    int n = len(s);
    vector<vector<mint>> dp(n + 1, vector<mint>(4));
    dp[0][0] = 1;
    REP(i, n){
        if(s[i] == '0' || s[i] == '?'){
            dp[i + 1][1] += dp[i][0];
            dp[i + 1][3] += dp[i][2];
        }
        if(s[i] == '1' || s[i] == '?'){
            dp[i + 1][2] += dp[i][1];
        }
        REP(j, 4){
            dp[i + 1][j] += dp[i][j] * (s[i] == '?' ? 2 : 1);
        }
    }

    cout << dp[n][3].a << endl;
}

int main(){
    int t = 1;
    //cin >> t;
    while(t--)solve();
}