#include <bits/stdc++.h>
using namespace std;
long long int gcd(long long int a, long long int b) {
  if (a < b)
    return gcd(b, a);
  else if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
long long int isPrime(long long int n) {
  long long int p = (long long int)sqrt(n);
  for (long long int i = (2); i <= (p); i += (1))
    if (n % i == 0) return 0;
  return 1;
}
long long int pow(long long int b, long long int e) {
  if (e == 0)
    return 1;
  else if (e % 2 == 0) {
    long long int a = pow(b, e / 2);
    return a * a;
  } else {
    long long int a = pow(b, e / 2);
    return b * a * a;
  }
}
long long int powm(long long int x, long long int y,
                   long long int m = 1000000007) {
  x = x % m;
  long long int res = 1;
  while (y) {
    if (y & 1) res = res * x;
    res %= m;
    y = y >> 1;
    x = x * x;
    x %= m;
  }
  return res;
}
long long int lcm(long long int a, long long int b) {
  return (a * b) / gcd(a, b);
}
long long int modInverse(long long int a, long long int m) {
  return powm(a, m - 2, m);
}
bool issq(long long int n) {
  long long int p = sqrt(n);
  return p * p == n;
}
vector<long long int> prime;
void seive(long long int n) {
  prime.resize(n + 1);
  for (long long int i = (2); i <= (n); i += (1))
    if (prime[i] == 0) {
      prime[i] = i;
      for (long long int j = (i * i); j <= (n); j += (i))
        if (prime[j] == 0) prime[j] = i;
    }
}
long long int extended_GCD(long long int a, long long int b, long long int &x,
                           long long int &y) {
  if (a == 0) {
    x = 0;
    y = 1;
    return b;
  }
  long long int x1, y1;
  long long int gcd = extended_GCD(b % a, a, x1, y1);
  x = y1 - (b / a) * x1;
  y = x1;
  return gcd;
}
long long int mulInv(long long int a, long long int mod = 1000000007) {
  long long int x, y;
  extended_GCD(a, mod, x, y);
  if (x < 0) x += mod;
  return x;
}
long long int find(long long int num[], long long int rem[], long long int k,
                   long long int prod) {
  long long int result = 0;
  for (long long int i = 0; i < k; i++) {
    long long int pp = prod / num[i];
    result += rem[i] * mulInv(pp, num[i]) * pp;
  }
  return result % prod;
}
class DSU {
 public:
  vector<long long int> a, rank;

 public:
  long long int c;
  map<string, long long int> m;

 public:
  DSU(long long int n) {
    c = 1;
    a.resize(n + 1);
    rank.resize(n + 1);
    for (long long int i = 1; i <= n; i++) a[i] = i;
  }

 public:
  long long int root(long long int x) {
    long long int u = x;
    while (a[x] != x) {
      a[x] = a[a[x]];
      x = a[x];
    }
    a[u] = x;
    return x;
  }

 public:
  void unite(long long int x, long long int y) {
    x = root(x);
    y = root(y);
    if (x != y) {
      if (rank[x] < rank[y])
        a[y] = x;
      else
        a[x] = y;
    }
  }
};
bool isSubSequence(string str1, string str2, int m, int n) {
  if (m == 0) return true;
  if (n == 0) return false;
  if (str1[m - 1] == str2[n - 1])
    return isSubSequence(str1, str2, m - 1, n - 1);
  return isSubSequence(str1, str2, m, n - 1);
}
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long int i, j, k, n, a, cap = 1, people = 0, sum = 0, sumv = 0, f = 0,
                               b = 0, flag = 0, fp = 0, bp = 0, ans = 0,
                               val = -1, first = 0, last, temp = 0;
  char ch, ch1;
  string s, s1;
  cin >> n >> k;
  ans = powm(2, (n + k), 998244353);
  cout << ans;
  return 0;
}
