func_code_string: #include <bits/stdc++.h>   using namespace std;   const int NUM = 2e5 + 5;   const int mod = 998244353;   int INF = 1e6;   pair<int, int> pinf = {INF, INF};   long long bin_pow(int n) {     if (n == 0) return 1;     if (n % 2 == 0) return bin_pow(n / 2) * bin_pow(n / 2) % mod;     return 2 * bin_pow(n - 1) % mod;   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(NULL);     int n, m;     cin >> m >> n;     string a, b;     cin >> b;     cin >> a;     reverse(a.begin(), a.end());     reverse(b.begin(), b.end());     long long s[m];     s[0] = (b[0] -  0 );     for (int i = 1; i < m; i++) {       s[i] = s[i - 1];       if (b[i] ==  1 ) s[i] += bin_pow(i);       s[i] %= mod;     }     long long ans = 0;     for (int i = 0; i < n; i++) {       if (a[i] ==  1 ) ans += s[min(i, m - 1)];       ans %= mod;     }     cout << ans;     return 0;   }   