#include <algorithm>
#include <bitset>
#include <tuple>
#include <cstdint>
#include <cstdio>
#include <cctype>
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <limits>
#include <map>
#include <memory>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
#define ArraySizeOf(array)     (sizeof(array) / sizeof(array[0]))
#define res(i,n) for(int i=n;;i++)
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define REP(i,n) for(int i=1;i<n;i++)
#define rev(i,n) for(int i=n-1;i>=0;i--)
#define REV(i,n) for(int i=n-1;i>0;i--)
#define req(i,n,m) for(int i=n;i<m;i++)
#define REQ(i,n,m,l) for(int i=n;i<m;i+=l)
long long INF = 1e9 + 7;
long long mod = 998244353;
long double PI = 3.141592653589793238462643383279502884197169399375105820974944592307816406286208998626034825342117;
unsigned NthDayOfWeekToDay(unsigned n, unsigned dow, unsigned dow1)
{
    unsigned day;
    if (dow < dow1) dow += 7;
    day = dow - dow1;
    day += 7 * n - 6;
    return day;
}
signed gcd(long long x, long long y) {
    if (y == 0)return x;
    return gcd(y, x % y);
}
signed lcm(long long x, long long y) {
    return x / gcd(x, y) * y;
}
unsigned DayToWeekNumber(unsigned day)
{
    return (day - 1) / 7 + 1;
}
unsigned AnotherDayOfWeek(unsigned day, unsigned day0, unsigned dow0)
{
    return (dow0 + 35 + day - day0) % 7;
}
long long RepeatSquaring(long long N, long long P, long long M) {
    if (P == 0) return 1;
    if (P % 2 == 0) {
        long long t = RepeatSquaring(N, P / 2, M);
        return t * t % M;
    }
    return N * RepeatSquaring(N, P - 1, M);
}
long long Fibonacci (long long A){
    vector<long long>B(A+1);B[0]=1;B[1]=1;
    for(int i=2;i<=A;i++){B[i]=B[i-1]+B[i-2];B[i]%=mod;}
    return B[A];
}
#define int long long
signed main() {
    int N, M; cin >> N >> M;
    if (N == 1) { cout << 1 << endl; return 0; }
    if (N > M) { cout << 1 << endl; return 0; }
    int count = M - N;
    cout <<Fibonacci(count+2)<< endl;
}