#include namespace { #pragma GCC diagnostic ignored "-Wunused-function" #include #pragma GCC diagnostic warning "-Wunused-function" using namespace std; using namespace atcoder; #define rep(i,n) for(int i = 0; i < (int)(n); i++) #define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--) #define all(x) begin(x), end(x) #define rall(x) rbegin(x), rend(x) template bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; } template bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; } using ll = long long; using P = pair; using VI = vector; using VVI = vector; using VL = vector; using VVL = vector; using mint = modint998244353; } int main() { ios::sync_with_stdio(false); cin.tie(0); string s; cin >> s; mint ans; array dp; dp[0] = 1; for(char c: s) { array ndp; if (c != '1') { rep(i, 4) ndp[i] += dp[i]; ndp[3] += dp[2]; ndp[1] += dp[0]; } if (c != '0') { rep(i, 4) ndp[i] += dp[i]; ndp[2] += dp[1]; } dp = ndp; } cout << dp[3].val() << '\n'; }