import java.io.InputStream; import java.util.Arrays; import java.util.function.IntUnaryOperator; import java.util.function.LongUnaryOperator; public class Main { public static void main(String[] args) throws Exception { ExtendedScanner sc = new ExtendedScanner(); FastPrintStream pw = new FastPrintStream(); solve(sc, pw); sc.close(); pw.flush(); pw.close(); } static final long MOD = Const.MOD998244353; static final ModArithmetic MA = ModArithmetic998244353.INSTANCE; public static void solve(ExtendedScanner sc, FastPrintStream pw) { int n = sc.nextInt(); long k = sc.nextLong(); long[] a = sc.longs(n); long s = 0; for (long e : a) { s += e; } s = MA.mod(s); long ans = MA.mul(s, MA.pow(2, k)); pw.println(ans); } } /** * @author https://atcoder.jp/users/suisen */ class FastScanner implements AutoCloseable { private final ByteBuffer tokenBuf = new ByteBuffer(); private final java.io.InputStream in; private final byte[] rawBuf = new byte[1 << 14]; private int ptr = 0; private int buflen = 0; public FastScanner(java.io.InputStream in) { this.in = in; } public FastScanner() { this(new java.io.FileInputStream(java.io.FileDescriptor.in)); } private final int readByte() { if (ptr < buflen) return rawBuf[ptr++]; ptr = 0; try { buflen = in.read(rawBuf); if (buflen > 0) { return rawBuf[ptr++]; } else { throw new java.io.EOFException(); } } catch (java.io.IOException e) { throw new java.io.UncheckedIOException(e); } } private final int readByteUnsafe() { if (ptr < buflen) return rawBuf[ptr++]; ptr = 0; try { buflen = in.read(rawBuf); if (buflen > 0) { return rawBuf[ptr++]; } else { return -1; } } catch (java.io.IOException e) { throw new java.io.UncheckedIOException(e); } } private final int skipUnprintableChars() { int b = readByte(); while (b <= 32 || b >= 127) b = readByte(); return b; } private final void loadToken() { tokenBuf.clear(); for (int b = skipUnprintableChars(); 32 < b && b < 127; b = readByteUnsafe()) { tokenBuf.append(b); } } public final boolean hasNext() { for (int b = readByteUnsafe(); b <= 32 || b >= 127; b = readByteUnsafe()) { if (b == -1) return false; } --ptr; return true; } public final String next() { loadToken(); return new String(tokenBuf.getRawBuf(), 0, tokenBuf.size()); } public final String nextLine() { tokenBuf.clear(); for (int b = readByte(); b != '\n'; b = readByteUnsafe()) { if (b == -1) break; tokenBuf.append(b); } return new String(tokenBuf.getRawBuf(), 0, tokenBuf.size()); } public final char nextChar() { return (char) skipUnprintableChars(); } public final char[] nextChars() { loadToken(); return tokenBuf.toCharArray(); } public final long nextLong() { long n = 0; boolean isNegative = false; int b = skipUnprintableChars(); if (b == '-') { isNegative = true; b = readByteUnsafe(); } if (b < '0' || '9' < b) throw new NumberFormatException(); while ('0' <= b && b <= '9') { // -9223372036854775808 - 9223372036854775807 if (n >= 922337203685477580l) { if (n > 922337203685477580l) { throw new ArithmeticException("long overflow"); } if (isNegative) { if (b >= '9') { throw new ArithmeticException("long overflow"); } n = -n - (b + '0'); b = readByteUnsafe(); if ('0' <= b && b <= '9') { throw new ArithmeticException("long overflow"); } else if (b <= 32 || b >= 127) { return n; } else { throw new NumberFormatException(); } } else { if (b >= '8') { throw new ArithmeticException("long overflow"); } n = n * 10 + b - '0'; b = readByteUnsafe(); if ('0' <= b && b <= '9') { throw new ArithmeticException("long overflow"); } else if (b <= 32 || b >= 127) { return n; } else { throw new NumberFormatException(); } } } n = n * 10 + b - '0'; b = readByteUnsafe(); } if (b <= 32 || b >= 127) return isNegative ? -n : n; throw new NumberFormatException(); } public final int nextInt() { long value = nextLong(); if ((int) value != value) { throw new ArithmeticException("int overflow"); } return (int) value; } public final double nextDouble() { return Double.parseDouble(next()); } public final void close() { try { in.close(); } catch (java.io.IOException e) { throw new java.io.UncheckedIOException(e); } } private static final class ByteBuffer { private static final int DEFAULT_BUF_SIZE = 1 << 12; private byte[] buf; private int ptr = 0; private ByteBuffer(int capacity) { this.buf = new byte[capacity]; } private ByteBuffer() { this(DEFAULT_BUF_SIZE); } private ByteBuffer append(int b) { if (ptr == buf.length) { int newLength = buf.length << 1; byte[] newBuf = new byte[newLength]; System.arraycopy(buf, 0, newBuf, 0, buf.length); buf = newBuf; } buf[ptr++] = (byte) b; return this; } private char[] toCharArray() { char[] chs = new char[ptr]; for (int i = 0; i < ptr; i++) { chs[i] = (char) buf[i]; } return chs; } private byte[] getRawBuf() { return buf; } private int size() { return ptr; } private void clear() { ptr = 0; } } } /** * @author https://atcoder.jp/users/suisen */ final class ExtendedScanner extends FastScanner { public ExtendedScanner() {super();} public ExtendedScanner(InputStream in) {super(in);} public int[] ints(final int n) { final int[] a = new int[n]; Arrays.setAll(a, $ -> nextInt()); return a; } public int[] ints(final int n, final IntUnaryOperator f) { final int[] a = new int[n]; Arrays.setAll(a, $ -> f.applyAsInt(nextInt())); return a; } public int[][] ints(final int n, final int m) { final int[][] a = new int[n][]; Arrays.setAll(a, $ -> ints(m)); return a; } public int[][] ints(final int n, final int m, final IntUnaryOperator f) { final int[][] a = new int[n][]; Arrays.setAll(a, $ -> ints(m, f)); return a; } public long[] longs(final int n) { final long[] a = new long[n]; Arrays.setAll(a, $ -> nextLong()); return a; } public long[] longs(final int n, final LongUnaryOperator f) { final long[] a = new long[n]; Arrays.setAll(a, $ -> f.applyAsLong(nextLong())); return a; } public long[][] longs(final int n, final int m) { final long[][] a = new long[n][]; Arrays.setAll(a, $ -> longs(m)); return a; } public long[][] longs(final int n, final int m, final LongUnaryOperator f) { final long[][] a = new long[n][]; Arrays.setAll(a, $ -> longs(m, f)); return a; } public char[][] charArrays(final int n) { final char[][] c = new char[n][]; Arrays.setAll(c, $ -> nextChars()); return c; } public double[] doubles(final int n) { final double[] a = new double[n]; Arrays.setAll(a, $ -> nextDouble()); return a; } public double[][] doubles(final int n, final int m) { final double[][] a = new double[n][]; Arrays.setAll(a, $ -> doubles(m)); return a; } public String[] strings(final int n) { final String[] s = new String[n]; Arrays.setAll(s, $ -> next()); return s; } } final class ModArithmetic998244353 extends ModArithmetic { public static final ModArithmetic INSTANCE = new ModArithmetic998244353(); private ModArithmetic998244353(){} public static final long MOD = Const.MOD998244353; public long getMod() {return MOD;} public long mod(long a) {return (a %= MOD) < 0 ? a + MOD : a;} public long add(long a, long b) {return (a += b) >= MOD ? a - MOD : a;} public long sub(long a, long b) {return (a -= b) < 0 ? a + MOD : a;} public long mul(long a, long b) {return (a * b) % MOD;} } /** * @author https://atcoder.jp/users/suisen */ class FastPrintStream implements AutoCloseable { private static final int INT_MAX_LEN = 11; private static final int LONG_MAX_LEN = 20; private int precision = 9; private static final int BUF_SIZE = 1 << 14; private static final int BUF_SIZE_MINUS_INT_MAX_LEN = BUF_SIZE - INT_MAX_LEN; private static final int BUF_SIZE_MINUS_LONG_MAX_LEN = BUF_SIZE - LONG_MAX_LEN; private final byte[] buf = new byte[BUF_SIZE]; private int ptr = 0; private final java.lang.reflect.Field strField; private final java.nio.charset.CharsetEncoder encoder; private final java.io.OutputStream out; public FastPrintStream(java.io.OutputStream out) { this.out = out; java.lang.reflect.Field f; try { f = java.lang.String.class.getDeclaredField("value"); f.setAccessible(true); } catch (NoSuchFieldException | SecurityException e) { f = null; } this.strField = f; this.encoder = java.nio.charset.StandardCharsets.US_ASCII.newEncoder(); } public FastPrintStream(java.io.File file) throws java.io.IOException { this(new java.io.FileOutputStream(file)); } public FastPrintStream(java.lang.String filename) throws java.io.IOException { this(new java.io.File(filename)); } public FastPrintStream() { this(new java.io.FileOutputStream(java.io.FileDescriptor.out)); } public FastPrintStream println() { if (ptr == BUF_SIZE) internalFlush(); buf[ptr++] = (byte) '\n'; return this; } public FastPrintStream println(java.lang.Object o) { return print(o).println(); } public FastPrintStream println(java.lang.String s) { return print(s).println(); } public FastPrintStream println(char[] s) { return print(s).println(); } public FastPrintStream println(char c) { return print(c).println(); } public FastPrintStream println(int x) { return print(x).println(); } public FastPrintStream println(long x) { return print(x).println(); } public FastPrintStream println(double d, int precision) { return print(d, precision).println(); } public FastPrintStream println(double d) { return print(d).println(); } private FastPrintStream print(byte[] bytes) { int n = bytes.length; if (ptr + n > BUF_SIZE) { internalFlush(); try { out.write(bytes); } catch (java.io.IOException e) { throw new java.io.UncheckedIOException(e); } } else { System.arraycopy(bytes, 0, buf, ptr, n); ptr += n; } return this; } public FastPrintStream print(java.lang.Object o) { return print(o.toString()); } public FastPrintStream print(java.lang.String s) { if (strField == null) { return print(s.getBytes()); } else { try { Object value = strField.get(s); if (value instanceof byte[]) { return print((byte[]) value); } else { return print((char[]) value); } } catch (IllegalAccessException e) { return print(s.getBytes()); } } } public FastPrintStream print(char[] s) { try { return print(encoder.encode(java.nio.CharBuffer.wrap(s)).array()); } catch (java.nio.charset.CharacterCodingException e) { byte[] bytes = new byte[s.length]; for (int i = 0; i < s.length; i++) { bytes[i] = (byte) s[i]; } return print(bytes); } } public FastPrintStream print(char c) { if (ptr == BUF_SIZE) internalFlush(); buf[ptr++] = (byte) c; return this; } public FastPrintStream print(int x) { if (ptr > BUF_SIZE_MINUS_INT_MAX_LEN) internalFlush(); if (-10 < x && x < 10) { if (x < 0) { buf[ptr++] = '-'; x = -x; } buf[ptr++] = (byte) ('0' + x); return this; } int d; if (x < 0) { if (x == Integer.MIN_VALUE) { buf[ptr++] = '-'; buf[ptr++] = '2'; buf[ptr++] = '1'; buf[ptr++] = '4'; buf[ptr++] = '7'; buf[ptr++] = '4'; buf[ptr++] = '8'; buf[ptr++] = '3'; buf[ptr++] = '6'; buf[ptr++] = '4'; buf[ptr++] = '8'; return this; } d = len(x = -x); buf[ptr++] = '-'; } else { d = len(x); } int j = ptr += d; while (x > 0) { buf[--j] = (byte) ('0' + (x % 10)); x /= 10; } return this; } public FastPrintStream print(long x) { if ((int) x == x) return print((int) x); if (ptr > BUF_SIZE_MINUS_LONG_MAX_LEN) internalFlush(); int d; if (x < 0) { if (x == Long.MIN_VALUE) { buf[ptr++] = '-'; buf[ptr++] = '9'; buf[ptr++] = '2'; buf[ptr++] = '2'; buf[ptr++] = '3'; buf[ptr++] = '3'; buf[ptr++] = '7'; buf[ptr++] = '2'; buf[ptr++] = '0'; buf[ptr++] = '3'; buf[ptr++] = '6'; buf[ptr++] = '8'; buf[ptr++] = '5'; buf[ptr++] = '4'; buf[ptr++] = '7'; buf[ptr++] = '7'; buf[ptr++] = '5'; buf[ptr++] = '8'; buf[ptr++] = '0'; buf[ptr++] = '8'; return this; } d = len(x = -x); buf[ptr++] = '-'; } else { d = len(x); } int j = ptr += d; while (x > 0) { buf[--j] = (byte) ('0' + (x % 10)); x /= 10; } return this; } public FastPrintStream print(double d, int precision) { if (d < 0) { print('-'); d = -d; } d += Math.pow(10, -precision) / 2; print((long) d).print('.'); d -= (long) d; for(int i = 0; i < precision; i++){ d *= 10; print((int) d); d -= (int) d; } return this; } public FastPrintStream print(double d) { return print(d, precision); } public void setPrecision(int precision) { this.precision = precision; } private void internalFlush() { try { out.write(buf, 0, ptr); ptr = 0; } catch (java.io.IOException e) { throw new java.io.UncheckedIOException(e); } } public void flush() { try { out.write(buf, 0, ptr); out.flush(); ptr = 0; } catch (java.io.IOException e) { throw new java.io.UncheckedIOException(e); } } public void close() { try { out.close(); } catch (java.io.IOException e) { throw new java.io.UncheckedIOException(e); } } private static int len(int x) { return x >= 1000000000 ? 10 : x >= 100000000 ? 9 : x >= 10000000 ? 8 : x >= 1000000 ? 7 : x >= 100000 ? 6 : x >= 10000 ? 5 : x >= 1000 ? 4 : x >= 100 ? 3 : x >= 10 ? 2 : 1; } private static int len(long x) { return x >= 1000000000000000000l ? 19 : x >= 100000000000000000l ? 18 : x >= 10000000000000000l ? 17 : x >= 1000000000000000l ? 16 : x >= 100000000000000l ? 15 : x >= 10000000000000l ? 14 : x >= 1000000000000l ? 13 : x >= 100000000000l ? 12 : x >= 10000000000l ? 11 : 10; } } class Const { public static final long LINF = 1l << 59; public static final int IINF = (1 << 30) - 1; public static final double DINF = 1e150; public static final double SMALL = 1e-12; public static final double MEDIUM = 1e-9; public static final double LARGE = 1e-6; public static final long MOD1000000007 = 1000000007; public static final long MOD998244353 = 998244353 ; public static final long MOD754974721 = 754974721 ; public static final long MOD167772161 = 167772161 ; public static final long MOD469762049 = 469762049 ; public static final int[] dx8 = {1, 0, -1, 0, 1, -1, -1, 1}; public static final int[] dy8 = {0, 1, 0, -1, 1, 1, -1, -1}; public static final int[] dx4 = {1, 0, -1, 0}; public static final int[] dy4 = {0, 1, 0, -1}; } /** * @author https://atcoder.jp/users/suisen */ abstract class ModArithmetic { public abstract long getMod(); public abstract long mod(long a); public abstract long add(long a, long b); public abstract long sub(long a, long b); public abstract long mul(long a, long b); public final long div(long a, long b) {return mul(a, inv(b));} public final long inv(long a) { a = mod(a); long b = getMod(); long u = 1, v = 0; while (b >= 1) { long t = a / b; a -= t * b; long tmp1 = a; a = b; b = tmp1; u -= t * v; long tmp2 = u; u = v; v = tmp2; } if (a != 1) throw new ArithmeticException("divide by zero"); return mod(u); } public final long fma(long a, long b, long c) {return add(mul(a, b), c);} public final long pow(long a, long b) { long pow = 1; for (a = mod(a); b > 0; b >>= 1, a = mul(a, a)) { if ((b & 1) == 1) pow = mul(pow, a); } return pow; } public final long add(long a, long b, long c) {return mod(a + b + c);} public final long add(long a, long b, long c, long d) {return mod(a + b + c + d);} public final long add(long a, long b, long c, long d, long e) {return mod(a + b + c + d + e);} public final long add(long a, long b, long c, long d, long e, long f) {return mod(a + b + c + d + e + f);} public final long add(long a, long b, long c, long d, long e, long f, long g) {return mod(a + b + c + d + e + f + g);} public final long add(long a, long b, long c, long d, long e, long f, long g, long h) {return mod(a + b + c + d + e + f + g + h);} public final long add(long... xs) {long s = 0; for (long x : xs) s += x; return mod(s);} public final long mul(long a, long b, long c) {return mul(a, mul(b, c));} public final long mul(long a, long b, long c, long d) {return mul(a, mul(b, mul(c, d)));} public final long mul(long a, long b, long c, long d, long e) {return mul(a, mul(b, mul(c, mul(d, e))));} public final long mul(long a, long b, long c, long d, long e, long f) {return mul(a, mul(b, mul(c, mul(d, mul(e, f)))));} public final long mul(long a, long b, long c, long d, long e, long f, long g) {return mul(a, mul(b, mul(c, mul(d, mul(e, mul(f, g))))));} public final long mul(long a, long b, long c, long d, long e, long f, long g, long h) {return mul(a, mul(b, mul(c, mul(d, mul(e, mul(f, mul(g, h)))))));} public final long mul(long... xs) {long s = 1; for (long x : xs) s = mul(s, x); return s;} public final java.util.OptionalLong sqrt(long a) { a = mod(a); if (a == 0) return java.util.OptionalLong.of(0); if (a == 1) return java.util.OptionalLong.of(1); long p = getMod(); if (pow(a, (p - 1) >> 1) != 1) { return java.util.OptionalLong.empty(); } if ((p & 3) == 3) { return java.util.OptionalLong.of(pow(a, (p + 1) >> 2)); } if ((p & 7) == 5) { if (pow(a, (p - 1) >> 2) == 1) { return java.util.OptionalLong.of(pow(a, (p + 3) >> 3)); } else { return java.util.OptionalLong.of(mul(pow(2, (p - 1) >> 2), pow(a, (p + 3) >> 3))); } } long S = 0, Q = p - 1; while ((Q & 1) == 0) { ++S; Q >>= 1; } long z = 1; while (pow(z, (p - 1) >> 1) != p - 1) ++z; long c = pow(z, Q), R = pow(a, (Q + 1) / 2), t = pow(a, Q), M = S; while (t != 1) { long cur = t; int i; for (i = 1; i < M; i++) { cur = mul(cur, cur); if (cur == 1) break; } long b = pow(c, 1l << (M - i - 1)); c = mul(b, b); R = mul(R, b); t = mul(t, b, b); M = i; } return java.util.OptionalLong.of(R); } /** array operations */ public final long[] rangeInv(int n) { final long MOD = getMod(); long[] invs = new long[n + 1]; if (n == 0) return invs; invs[1] = 1; for (int i = 2; i <= n; i++) { invs[i] = mul(MOD - MOD / i, invs[(int) (MOD % i)]); } return invs; } public final long[] arrayInv(long[] a) { int n = a.length; long[] l = new long[n + 1]; long[] r = new long[n + 1]; l[0] = r[n] = 1; for (int i = 0; i < n; i++) l[i + 1] = mul(l[i], a[i ]); for (int i = n; i > 0; i--) r[i - 1] = mul(r[i], a[i - 1]); long invAll = inv(l[n]); long[] invs = new long[n]; for (int i = 0; i < n; i++) { invs[i] = mul(l[i], r[i + 1], invAll); } return invs; } public final long[] factorial(int n) { long[] ret = new long[n + 1]; ret[0] = 1; for (int i = 1; i <= n; i++) ret[i] = mul(ret[i - 1], i); return ret; } public final long[] factorialInv(int n) { long facN = 1; for (int i = 2; i <= n; i++) facN = mul(facN, i); long[] invs = new long[n + 1]; invs[n] = inv(facN); for (int i = n; i > 0; i--) invs[i - 1] = mul(invs[i], i); return invs; } public final long[] rangePower(long a, int n) { a = mod(a); long[] pows = new long[n + 1]; pows[0] = 1; for (int i = 1; i <= n; i++) pows[i] = mul(pows[i - 1], a); return pows; } public final long[] rangePowerInv(long a, int n) { a = mod(a); long[] invs = new long[n + 1]; invs[n] = inv(pow(a, n)); for (int i = n; i > 0; i--) invs[i - 1] = mul(invs[i], a); return invs; } /** combinatric operations */ public final long[][] combTable(int n) { long[][] comb = new long[n + 1][]; for (int i = 0; i <= n; i++) { comb[i] = new long[i + 1]; comb[i][0] = comb[i][i] = 1; for (int j = 1; j < i; j++) { comb[i][j] = add(comb[i - 1][j - 1], comb[i - 1][j]); } } return comb; } public final long comb(int n, int r, long[] fac, long[] facInv) { return r < 0 || r > n ? 0 : mul(fac[n], facInv[r], facInv[n - r]); } public final long naiveComb(long n, long r) { if (r < 0 || r > n) return 0; r = Math.min(r, n - r); long num = 1, den = 1; for (int i = 0; i < r; i++) { num = mul(num, n - i); den = mul(den, i + 1); } return div(num, den); } public final long perm(int n, int r, long[] fac, long[] facInv) { return r < 0 || r > n ? 0 : mul(fac[n], facInv[n - r]); } public final long naivePerm(long n, long r) { if (r < 0 || r > n) return 0; long res = 1; for (long i = 0; i < r; i++) res = mul(res, n - i); return res; } }