import java.io.*; import java.util.*; import java.util.function.IntUnaryOperator; import java.util.function.LongUnaryOperator; import java.util.stream.Collectors; public class Main { static In in = new FastIn(); static Out out = new Out(false); static final long inf = 0x1fffffffffffffffL; static final int iinf = 0x3fffffff; static final double eps = 1e-9; static long mod = 998244353; void solve() { long n = in.nextLong(); int m = in.nextInt(); if (n < m) { out.println(0); return; } long ans = Combination.pow(2, n); long a = 1; long b = 1; for (int i = 0; i < m; i++) { ans = (ans + mod - a * Combination.inv(b) % mod) % mod; b *= i + 1; a *= n - i; a %= mod; b %= mod; } out.println(ans); } static class Combination { private static final int MEMO_THRESHOLD = 1000000; static long mod = Main.mod; private static final List inv = new ArrayList<>(); private static final List fact = new ArrayList<>(); private static final List invFact = new ArrayList<>(); private static final Map> pow = new HashMap<>(); private static void buildInvTable(int n) { if (inv.isEmpty()) { inv.add(null); inv.add(1L); } for (int i = inv.size(); i <= n; i++) { inv.add(mod - inv.get((int)(mod % i)) * (mod / i) % mod); } } private static void buildFactTable(int n) { if (fact.isEmpty()) { fact.add(1L); invFact.add(1L); } for (int i = fact.size(); i <= n; i++) { fact.add(fact.get(i - 1) * i % mod); invFact.add(inv(fact.get(i))); } } public static void setupPowTable(long a) { pow.put(a, new ArrayList<>(Collections.singleton(1L))); } private static void rangeCheck(long n, long r) { if (n < r) { throw new IllegalArgumentException("n < r"); } if (n < 0) { throw new IllegalArgumentException("n < 0"); } if (r < 0) { throw new IllegalArgumentException("r < 0"); } } static long fact(int n) { buildFactTable(n); return fact.get(n); } static long invFact(int n) { buildFactTable(n); return invFact.get(n); } private static long comb0(int n, int r) { rangeCheck(n, r); return fact(n) * invFact(r) % mod * invFact(n - r) % mod; } static long comb(long n, long r) { rangeCheck(n, r); if (n < MEMO_THRESHOLD) { return comb0((int)n, (int)r); } r = Math.min(r, n - r); long x = 1, y = 1; for (long i = 1; i <= r; i++) { x = x * (n - r + i) % mod; y = y * i % mod; } return x * inv(y) % mod; } private static long perm0(int n, int r) { rangeCheck(n, r); return fact(n) * invFact(n - r) % mod; } static long perm(long n, long r) { rangeCheck(n, r); if (n < MEMO_THRESHOLD) { return perm0((int)n, (int)r); } long x = 1; for (long i = 1; i <= r; i++) { x = x * (n - r + i) % mod; } return x; } static long homo(long n, long r) { return r == 0 ? 1 : comb(n + r - 1, r); } private static long inv0(int a) { buildInvTable(a); return inv.get(a); } static long inv(long a) { if (a < MEMO_THRESHOLD) { return inv0((int)a); } long b = mod; long u = 1, v = 0; while (b >= 1) { long t = a / b; a -= t * b; u -= t * v; if (a < 1) { return (v %= mod) < 0 ? v + mod : v; } t = b / a; b -= t * a; v -= t * u; } return (u %= mod) < 0 ? u + mod : u; } static long pow(long a, long b) { if (pow.containsKey(a) && b < MEMO_THRESHOLD) { return powMemo(a, (int)b); } long x = 1; while (b > 0) { if (b % 2 == 1) { x = x * a % mod; } a = a * a % mod; b >>= 1; } return x; } static long powMemo(long a, int b) { List powMemo = pow.get(a); while (powMemo.size() <= b) { powMemo.add(powMemo.get(powMemo.size() - 1) * a % Main.mod); } return powMemo.get(b); } } public static void main(String... args) { new Main().solve(); out.flush(); } } class FastIn extends In { private final BufferedInputStream reader = new BufferedInputStream(System.in); private final byte[] buffer = new byte[0x10000]; private int i = 0; private int length = 0; public int read() { if (i == length) { i = 0; try { length = reader.read(buffer); } catch (IOException ignored) { } if (length == -1) { return 0; } } if (length <= i) { throw new RuntimeException(); } return buffer[i++]; } String next() { StringBuilder builder = new StringBuilder(); int b = read(); while (b < '!' || '~' < b) { b = read(); } while ('!' <= b && b <= '~') { builder.appendCodePoint(b); b = read(); } return builder.toString(); } String nextLine() { StringBuilder builder = new StringBuilder(); int b = read(); while (b != 0 && b != '\r' && b != '\n') { builder.appendCodePoint(b); b = read(); } if (b == '\r') { read(); } return builder.toString(); } int nextInt() { long val = nextLong(); if ((int)val != val) { throw new NumberFormatException(); } return (int)val; } long nextLong() { int b = read(); while (b < '!' || '~' < b) { b = read(); } boolean neg = false; if (b == '-') { neg = true; b = read(); } long n = 0; int c = 0; while ('0' <= b && b <= '9') { n = n * 10 + b - '0'; b = read(); c++; } if (c == 0 || c >= 2 && n == 0) { throw new NumberFormatException(); } return neg ? -n : n; } } class In { private final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in), 0x10000); private StringTokenizer tokenizer; String next() { try { while (tokenizer == null || !tokenizer.hasMoreTokens()) { tokenizer = new StringTokenizer(reader.readLine()); } } catch (IOException ignored) { } return tokenizer.nextToken(); } int nextInt() { return Integer.parseInt(next()); } long nextLong() { return Long.parseLong(next()); } double nextDouble() { return Double.parseDouble(next()); } char[] nextCharArray() { return next().toCharArray(); } String[] nextStringArray(int n) { String[] s = new String[n]; for (int i = 0; i < n; i++) { s[i] = next(); } return s; } char[][] nextCharGrid(int n, int m) { char[][] a = new char[n][m]; for (int i = 0; i < n; i++) { a[i] = next().toCharArray(); } return a; } int[] nextIntArray(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) { a[i] = nextInt(); } return a; } int[] nextIntArray(int n, IntUnaryOperator op) { int[] a = new int[n]; for (int i = 0; i < n; i++) { a[i] = op.applyAsInt(nextInt()); } return a; } int[][] nextIntMatrix(int h, int w) { int[][] a = new int[h][w]; for (int i = 0; i < h; i++) { a[i] = nextIntArray(w); } return a; } long[] nextLongArray(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) { a[i] = nextLong(); } return a; } long[] nextLongArray(int n, LongUnaryOperator op) { long[] a = new long[n]; for (int i = 0; i < n; i++) { a[i] = op.applyAsLong(nextLong()); } return a; } long[][] nextLongMatrix(int h, int w) { long[][] a = new long[h][w]; for (int i = 0; i < h; i++) { a[i] = nextLongArray(w); } return a; } List> nextEdges(int n, int m, boolean directed) { List> res = new ArrayList<>(); for (int i = 0; i < n; i++) { res.add(new ArrayList<>()); } for (int i = 0; i < m; i++) { int u = nextInt() - 1; int v = nextInt() - 1; res.get(u).add(v); if (!directed) { res.get(v).add(u); } } return res; } } class Out { private final PrintWriter out = new PrintWriter(System.out); private final PrintWriter err = new PrintWriter(System.err); boolean autoFlush = false; boolean enableDebug; Out(boolean enableDebug) { this.enableDebug = enableDebug; } void println(Object... args) { if (args == null || args.getClass() != Object[].class) { args = new Object[] {args}; } out.println(Arrays.stream(args).map(obj -> { Class clazz = obj == null ? null : obj.getClass(); return clazz == Double.class ? String.format("%.10f", obj) : clazz == byte[].class ? Arrays.toString((byte[])obj) : clazz == short[].class ? Arrays.toString((short[])obj) : clazz == int[].class ? Arrays.toString((int[])obj) : clazz == long[].class ? Arrays.toString((long[])obj) : clazz == char[].class ? Arrays.toString((char[])obj) : clazz == float[].class ? Arrays.toString((float[])obj) : clazz == double[].class ? Arrays.toString((double[])obj) : clazz == boolean[].class ? Arrays.toString((boolean[])obj) : obj instanceof Object[] ? Arrays.deepToString((Object[])obj) : String.valueOf(obj); }).collect(Collectors.joining(" "))); if (autoFlush) { out.flush(); } } void debug(Object... args) { if (!enableDebug) { return; } if (args == null || args.getClass() != Object[].class) { args = new Object[] {args}; } err.println(Arrays.stream(args).map(obj -> { Class clazz = obj == null ? null : obj.getClass(); return clazz == Double.class ? String.format("%.10f", obj) : clazz == byte[].class ? Arrays.toString((byte[])obj) : clazz == short[].class ? Arrays.toString((short[])obj) : clazz == int[].class ? Arrays.toString((int[])obj) : clazz == long[].class ? Arrays.toString((long[])obj) : clazz == char[].class ? Arrays.toString((char[])obj) : clazz == float[].class ? Arrays.toString((float[])obj) : clazz == double[].class ? Arrays.toString((double[])obj) : clazz == boolean[].class ? Arrays.toString((boolean[])obj) : obj instanceof Object[] ? Arrays.deepToString((Object[])obj) : String.valueOf(obj); }).collect(Collectors.joining(" "))); err.flush(); } void println(char a) { out.println(a); if (autoFlush) { out.flush(); } } void println(int a) { out.println(a); if (autoFlush) { out.flush(); } } void println(long a) { out.println(a); if (autoFlush) { out.flush(); } } void println(double a) { out.println(String.format("%.10f", a)); if (autoFlush) { out.flush(); } } void println(String s) { out.println(s); if (autoFlush) { out.flush(); } } void println(char[] s) { out.println(String.valueOf(s)); if (autoFlush) { out.flush(); } } void println(int[] a) { StringJoiner joiner = new StringJoiner(" "); for (int i : a) { joiner.add(Integer.toString(i)); } out.println(joiner); if (autoFlush) { out.flush(); } } void println(long[] a) { StringJoiner joiner = new StringJoiner(" "); for (long i : a) { joiner.add(Long.toString(i)); } out.println(joiner); if (autoFlush) { out.flush(); } } void flush() { err.flush(); out.flush(); } }