import java.util.Scanner;

public class Main {
    static final int MOD = 998244353;
    static final int MAX_V = 2000001;
    static long[] fac = new long[MAX_V];
    static long[] finv = new long[MAX_V];
    static long[] inv = new long[MAX_V];

    public static void main(String[] args) {
        precompute();

        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int M = sc.nextInt();

        long[] cumnoc = new long[M + 2]; // M + 2 to avoid IndexOutOfBounds in cumnoc[i+1]
        for (int i = 0; i <= M; i++) {
            if ((long) i * N > M) break;
            cumnoc[i] = fac[M - i * N + N];
            cumnoc[i] = cumnoc[i] * finv[N] % MOD;
            cumnoc[i] = cumnoc[i] * finv[M - i * N] % MOD;
        }

        if (N == 1) {
            for (int i = 0; i <= M; i++) {
                cumnoc[i] = (cumnoc[i] - N + MOD) % MOD;
            }
        } else {
            cumnoc[0] = (cumnoc[0] - N + MOD) % MOD;
        }

        long[] noc = new long[M];
        for (int i = 0; i < M; i++) {
            noc[i] = (cumnoc[i] - cumnoc[i + 1] + MOD) % MOD;
        }

        long ans = 0;
        for (int i = 0; i < M; i++) {
            ans = (ans + i * noc[i]) % MOD;
        }

        long total = cumnoc[0];
        ans = ans * modinv(total) % MOD;
        System.out.println(ans);
    }

    static void precompute() {
        fac[0] = fac[1] = 1;
        finv[0] = finv[1] = 1;
        inv[1] = 1;

        for (int i = 2; i < MAX_V; i++) {
            fac[i] = fac[i - 1] * i % MOD;
            inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
            finv[i] = finv[i - 1] * inv[i] % MOD;
        }
    }

    static long modinv(long a) {
        return modpow(a, MOD - 2);
    }

    static long modpow(long base, long exp) {
        long result = 1;
        base %= MOD;
        while (exp > 0) {
            if ((exp & 1) == 1) result = result * base % MOD;
            base = base * base % MOD;
            exp >>= 1;
        }
        return result;
    }
}