#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
const int inf = 1e9;
const long long int INF = 1e18;
const double PI = acos(-1.0);
const double EPS = 1e-8;
const int MOD = 998244353;
struct debugger {
  template <typename T>
  debugger& operator,(const T& v) {
    cerr << v << " ";
    return *this;
  }
} dbg;
long long int P[2 * N];
int on[2 * N];
long long int ans;
long long int BigMod(long long int b, long long int p, long long int mod) {
  long long int res = 1 % mod, x = b % mod;
  while (p) {
    if (p & 1) res = (res * x) % mod;
    x = (x * x) % mod;
    p >>= 1;
  }
  return (res % mod);
}
void genPow() {
  P[0] = 1LL;
  for (int i = 1; i <= 2 * N - 1; i++)
    P[i] = (P[i - 1] % MOD * 2LL % MOD) % MOD;
}
int main(int argc, char const* argv[]) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ;
  genPow();
  int n, m;
  string a, b;
  cin >> n >> m;
  cin >> a >> b;
  while (a.size() < b.size()) a = '0' + a;
  while (b.size() < a.size()) b = '0' + b;
  for (int i = 0; i < b.size(); i++) {
    if (i == 0)
      on[i] = (b[i] == '1');
    else
      on[i] += on[i - 1] + (b[i] == '1');
  }
  for (int i = 0, p = a.size() - 1; i < a.size(); i++, p--) {
    if (a[i] == '1') {
      ans = (ans % MOD + on[i] % MOD * P[p] % MOD) % MOD;
    }
  }
  cout << ans << endl;
  return 0;
}
