#include <cstdio> const int Mod = 998244353; int x = 1, y = 2; char ch; signed main() { ch = getchar(); while (1) { ch = getchar(); if (ch == '0') x = 3ll * x % Mod, y = (y << 1) % Mod; else if (ch == '1') x = (3ll * x + 2 * y) % Mod; else break; } printf("%d\n", (x + y) % Mod); return 0; }