#include <bits/stdc++.h> #define int long long using namespace std; const int md = 998244353; string s; int n,a[1000006],f[1000006][4]; signed main () { cin >> s; n = s.length(); for (int i = 0;i < n;i++) { a[i + 1] = s[i] - '0'; } f[1][0] = 2; f[1][1] = 1; for (int i = 2;i <= n;i++) { if (a[i]) { f[i][0] = f[i - 1][0]; f[i][1] = f[i - 1][1] * 3 + f[i - 1][0] * 2; } else { f[i][0] = f[i - 1][0] * 2; f[i][1] = f[i - 1][1] * 3; } f[i][0] %= md; f[i][1] %= md; } int ans = (f[n][0] + f[n][1]) % md; cout << ans << endl; return 0; }