#include <iostream>
#include <queue>
#include <stack>
#include <vector>
#include <deque>
#include <set>
#include <map>
#include <unordered_map>
#include <cassert>
#include <algorithm>
#include <cmath>
#include <random>
#include <ctime>
#include <cstdlib>
#include <chrono>

using namespace std;

const int MOD = 998244353;

struct matrice {
  int n, m;
  int a[4][4];

  matrice(int n_, int m_) : n(n_), m(m_) {
    for (int i = 0; i < n; ++i) {
      for (int j = 0; j < m; ++j)
        a[i][j] = 0;
    }
  }

  int* operator [] (int i) {
    return a[i];
  }

  matrice& operator *= (matrice &rhs) {
    matrice tmp(n, rhs.m);
    for (int i = 0; i < n; ++i) {
      for (int j = 0; j < m; ++j) {
        for (int k = 0; k < rhs.m; ++k) {
          tmp[i][k] = (tmp[i][k] + 1LL * a[i][j] * rhs[j][k]) % MOD;
        }
      }
    }

    for (int i = 0; i < n; ++i) {
      for (int j = 0; j < m; ++j) {
        a[i][j] = tmp[i][j];
      }
    }

    n = tmp.n;
    m = tmp.m;

    return *this;
  }
};

int ct;
map<int, int> dp;

bool is_ok(int x) {
  if ((x & 1) && (x & 4) && (x & 2))
    return false;

  if ((x & 1) && (x & 4))
    return true;

  if (x & 2)
    return true;

  return false;
}

int get_ct(int n) {
  vector<matrice> dp;
  for (int i = 0; i < 4; ++i) {
    dp.emplace_back(matrice(1, 4));
    dp[i][0][i] = 1;
  }

  matrice t(4, 4);

  t[1][2] = 1;
  t[1][3] = 1;
  t[2][1] = 1;
  t[3][2] = 1;

  n -= 2;
  for (int p = 1; p <= n; p <<= 1) {
    if (p & n) {
      for (int i = 0; i < 4; ++i)
        dp[i] *= t;
    }
    t *= t;
  }

  int ans = 0;
  for (int i = 0; i < 4; ++i) {
    for (int j = 0; j < 4; ++j) {
      if (is_ok((i) | ((j & 1) << 2)) && is_ok(((i & 2) >> 1) | (j << 1))) {
        ans = (ans + dp[i][0][j]) % MOD;
      }
    }
  }

  return ans;
}

int solve(int m) {
  if (m < 0)
    return 0;
  if (m == 0)
    return 1;

  if (dp.count(m)) {
    return dp[m];
  }

  if (m % 2 == 0) {
    return dp[m] = (solve(m / 2) + solve(m / 2 - 1)) % MOD;
  }

  return dp[m] = 1LL * solve(m / 2) * ct % MOD;
}

void solve() {
  int n, m;
  cin >> n >> m;

  ct = get_ct(n);

  cout << solve(m) << "\n";
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);

  int t = 1;
  while (t--)
    solve();

  return 0;
}