func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     string a, b;     int n, m;     cin >> n >> m;     cin >> a >> b;     int pw = 1;     int ans = 0, res = 0;     for (int i = 0; i < m; i++) {       if (i < n && a[n - i - 1] ==  1 ) res = (res + pw) % 998244353;       if (b[m - i - 1] ==  1 ) ans = (ans + res) % 998244353;       pw = (pw + pw) % 998244353;     }     cout << ans << endl;     return 0;   }   