#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
using ll = long long;
using ull = unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)


const ll M = 998244353;

ll solve(ll K){
  if(K == 0) return 0;
  if(K == 1) return 1;
  int d=0; while((K>>(d+1)) != 0) d++;
  ll res = 1;
  rep(t,d) res = res * 3 % M;
  res += solve(K - (1ll << d)) * 2;
  res %= M;
  return res;
}

int main(){
  ll N, K; cin >> N >> K;
  ll ans = 0;
  if(N % 2 == 0){
    ans = solve(K/2+N/2+1);
    ans = ans + M - solve(K/2);
    ans %= M;
    if(K % 2 == 1) ans = ans * 2 % M;
  }
  else{
    ans = solve(K+N+1);
    ans = ans + M - solve(K);
    ans %= M;
  }
  cout << ans << "\n";
  return 0;
}



struct ios_do_not_sync{
  ios_do_not_sync(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
  }
} ios_do_not_sync_instance;