using System; using System.Collections.Generic; using System.Collections.ObjectModel; using System.Diagnostics; using System.Runtime.CompilerServices; using System.IO; using System.Linq; using System.Numerics; using static Solve.Methods; using static Solve.Input; using static Solve.Output; using static System.Math;   using Solve.Libraries.ModInt;   namespace Solve { public partial class Solver {  public void Main() { var n = Int.r; var k = Long.r; var a = Long.array(n);  var ans = new ModInt(0); foreach (long l in a) { ans += l; }  print(ans * ModInt.ModPow(2, k)); } public const int MOD = 1000000007; }  public static class Methods { [MethodImpl(256)] public static bool Assert(in bool b, in string message = null) => b ? true : throw new Exception(message ?? "Assert failed."); [MethodImpl(256)] public static string JoinSpace<T>(this IEnumerable<T> source) => source.Join(" "); [MethodImpl(256)] public static string JoinEndline<T>(this IEnumerable<T> source) => source.Join("\n"); [MethodImpl(256)] public static string Join<T>(this IEnumerable<T> source, string s) => string.Join(s, source); [MethodImpl(256)] public static string Join<T>(this IEnumerable<T> source, char c) => string.Join(c.ToString(), source); public static int Gcd(int a, int b) => (int) Gcd((long) a, b); public static long Gcd(long a, long b) { while (true) { if (a < b) (a, b) = (b, a); if (a % b == 0) return b; (a, b) = (b, a % b); } } public static long Lcm(long a, long b) => a / Gcd(a, b) * b; public static bool IsPrime(long value) { if (value <= 1) return false; for (long i = 2; i * i <= value; ++i) if (value % i == 0) return false; return true; } public static long Pow(long a, int b) { long res = 1; while (b > 0) { if (b % 2 != 0) res *= a; a *= a; b >>= 1; } return res; } public static int PowMod(long a, long b, int p) => (int) PowMod(a, b, (long) p); public static long PowMod(long a, long b, long p) { long res = 1; while (b > 0) { if (b % 2 != 0) res = res * a % p; a = a * a % p; b >>= 1; } return res; } public static IEnumerable<long> Factors(long n) { Assert(n >= 0, "n must be greater than 0."); for (long i = 1; i * i <= n; ++i) { var div = DivRem(n, i, out var rem); if (rem > 0) continue; yield return div; if (i != div) yield return i; } } public static IEnumerable<int> Factors(int n) => Factors((long) n).Select(Convert.ToInt32); [MethodImpl(256)] public static int DivCeil(int a, int b) => (a + b - 1) / b; [MethodImpl(256)] public static long DivCeil(long a, long b) => (a + b - 1) / b; public static IEnumerable<T[]> Permutations<T>(IEnumerable<T> src) { var ret = new List<T[]>(); Search(ret, new Stack<T>(), src.ToArray()); return ret;  static void Search(ICollection<T[]> perms, Stack<T> stack, T[] a) { int N = a.Length; if (N == 0) perms.Add(stack.Reverse().ToArray()); else { var b = new T[N - 1]; Array.Copy(a, 1, b, 0, N - 1); for (int i = 0; i < a.Length; ++i) { stack.Push(a[i]); Search(perms, stack, b); if (i < b.Length) b[i] = a[i]; stack.Pop(); } } } } public static long BinarySearch(long low, long high, Func<long, bool> expression) { while (low < high) { long middle = (high - low) / 2 + low; if (!expression(middle)) high = middle; else low = middle + 1; }  return high; } public static int LowerBound<T>(T[] arr, int start, int end, T value, IComparer<T> comparer) { int low = start; int high = end; while (low < high) { var mid = ((high - low) >> 1) + low; if (comparer.Compare(arr[mid], value) < 0) low = mid + 1; else high = mid; }  return low; } public static int LowerBound<T>(T[] arr, T value) where T : IComparable => LowerBound(arr, 0, arr.Length, value, Comparer<T>.Default); public static int UpperBound<T>(T[] arr, int start, int end, T value, IComparer<T> comparer) { var (low, high) = (start, end); while (low < high) { var mid = ((high - low) >> 1) + low; if (comparer.Compare(arr[mid], value) <= 0) low = mid + 1; else high = mid; }  return low; } public static int UpperBound<T>(T[] arr, T value) =>  UpperBound(arr, 0, arr.Length, value, Comparer<T>.Default); [MethodImpl(256)] public static IEnumerable<TResult> Repeat<TResult>(TResult value, int count) => Enumerable.Repeat(value, count); [MethodImpl(256)] public static string AsString(this IEnumerable<char> source) => new string(source.ToArray()); public static IEnumerable<long> CumSum(this IEnumerable<long> source) { long sum = 0; foreach (var item in source) yield return sum += item; } public static IEnumerable<int> CumSum(this IEnumerable<int> source) { int sum = 0; foreach (var item in source) yield return sum += item; } [MethodImpl(256)] public static bool IsIn<T>(this T value, T l, T r) where T : IComparable<T> => l.CompareTo(r) > 0 ? throw new ArgumentException() : l.CompareTo(value) <= 0 && value.CompareTo(r) < 0; [MethodImpl(256)] public static bool IsIn(this in int value, in Range range) => value.IsIn(range.Start.Value, range.End.Value); [MethodImpl(256)] public static bool IsIn(this in Index value, in Range range) => value.IsFromEnd && value.Value.IsIn(range.Start.Value, range.End.Value); public static IEnumerable<int> Range(int start, int end, int step = 1) { for (var i = start; i < end; i += step) yield return i; } public static IEnumerable<int> Range(int end) => Range(0, end); public static IEnumerable<int> Range(Range range, int step = 1) => Range(range.Start.Value, range.End.Value, step); [MethodImpl(256)] public static T[] Sort<T>(this T[] arr) where T : IComparable<T> { var array = arr[..]; Array.Sort(array); return array; } [MethodImpl(256)] public static T[] Sort<T, U>(this T[] arr, Func<T, U> selector) where U : IComparable<U> { var array = arr[..]; Array.Sort(array, (a, b) => selector(a).CompareTo(selector(b))); return array; } [MethodImpl(256)] public static T[] SortDescending<T>(this T[] arr) where T : IComparable<T> { var array = arr[..]; Array.Sort(array, (a, b) => b.CompareTo(a)); return array; } [MethodImpl(256)] public static T[] SortDescending<T, U>(this T[] arr, Func<T, U> selector) where U : IComparable<U> { var array = arr[..]; Array.Sort(array, (a, b) => selector(b).CompareTo(selector(a))); return array; } public static T[] Unique<T>(this IEnumerable<T> arr) { var source = arr.ToArray(); var ret = new List<T>(source.Length); var set = new SortedSet<T>(); ret.AddRange(source.Where(val => set.Add(val)));  return ret.ToArray(); } [MethodImpl(256)] public static bool chmin<T>(ref T a, T b) where T : IComparable<T> { if (a.CompareTo(b) > 0) { a = b; return true; } return false; }  [MethodImpl(256)] public static bool chmax<T>(ref T a, T b) where T : IComparable<T> { if (a.CompareTo(b) < 0) { a = b; return true; } return false; } public static T[] InitArray<T>(int n, Func<int, T> init) { var res = new T[n]; for (int i = 0; i < n; i++) res[i] = init(i); return res; } public static T[][] JaggedArray2D<T>(int a, int b, T defaultValue = default) { var ret = new T[a][]; for (int i = 0; i < a; ++i) ret[i] = Enumerable.Repeat(defaultValue, b).ToArray(); return ret; } public static T[,] Array2D<T>(int a, int b, T defaultValue = default) { var ret = new T[a, b]; for (int i = 0; i < a; ++i) for (int j = 0; j < b; ++j) ret[i, j] = defaultValue; return ret; } public static T[,] To2DArray<T>(this T[][] array) { if (!array.Any()) return new T[0, 0];  int len = array[0].Length; if (array.Any(x => x.Length != len)) throw new ArgumentException("Length of each array must be same.", nameof(array));  var ret = new T[array.Length, len]; for (int i = 0; i < array.Length; ++i) for (int j = 0; j < len; ++j) ret[i, j] = array[i][j]; return ret; } [MethodImpl(256)] public static T Min<T>(params T[] col) => col.Min(); [MethodImpl(256)] public static T Max<T>(params T[] col) => col.Max(); [MethodImpl(256)] public static IEnumerable<(T, int)> WithIndex<T>(this IEnumerable<T> source) => source.Select((x, i) => (x, i)); [MethodImpl(256)] public static (T, U, V)[] Zip<T, U, V>( IReadOnlyCollection<T> t, IReadOnlyCollection<U> u, IReadOnlyCollection<V> v ) { Assert(t.Count == u.Count && u.Count == v.Count); return t.Zip(u, (a, b) => (a, b)) .Zip(v, (tuple, c) => (tuple.Item1, tuple.Item2, c)).ToArray(); } [MethodImpl(256)] public static void rep(in int start, in int end, Action<int> func) { for (int i = start; i < end; ++i) func(i); } [MethodImpl(256)] public static void rep(in int end, Action<int> func) => rep(0, end, func); [MethodImpl(256)] public static void rep1(in int end, Action<int> func) => rep(1, end + 1, func); [MethodImpl(256)] public static void repr(in int end, Action<int> func) { for (int i = end - 1; i >= 0; --i) func(i); } [MethodImpl(256)] public static void each<T>(this IEnumerable<T> source, Action<T> func) { foreach (var item in source) func(item); } [MethodImpl(256)] public static void eachWithIndex<T>(this IEnumerable<T> source, Action<T, int> func) { int index = 0; foreach (var item in source) func(item, index++); } [MethodImpl(256)] public static int bit(in int x) => 1 << x; [MethodImpl(256)] public static long bitl(in int x) => 1L << x; } public class UnorderedMap<T, U> : Dictionary<T, U> { public new U this[T k] { get => TryGetValue(k, out var v) ? v : base[k] = default; set => base[k] = value; } } public class Map<T, U> : SortedDictionary<T, U> { readonly U _default; public Map(U defaultValue = default) { _default = defaultValue; } public new U this[T k] { get => TryGetValue(k, out var v) ? v : base[k] = _default; set => base[k] = value; } } public class Scanner<T> { public T r => next<T>(); public T next() => r;  IEnumerable<T> enumerable(int N) { for (int i = 0; i < N; ++i) yield return r; }  public T[] array(in int N) => enumerable(N).ToArray(); public List<T> list(in int N) => enumerable(N).ToList(); public T[,] array2d(in int N, in int M) => next2DArray<T>(N, M); public T[][] listArray(in int n) { var ret = new T[n][]; for (int i = 0; i < n; i++) ret[i] = array(next<int>()); return ret; }  public void Deconstruct(out T _1, out T _2) => (_1, _2) = (r, r); public void Deconstruct(out T _1, out T _2, out T _3) => (_1, _2, _3) = (r, r, r); public void Deconstruct(out T _1, out T _2, out T _3, out T _4) => (_1, _2, _3, _4) = (r, r, r, r); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5) => (_1, _2, _3, _4, _5) = (r, r, r, r, r); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5, out T _6) => (_1, _2, _3, _4, _5, _6) = (r, r, r, r, r, r); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5, out T _6, out T _7) => (_1, _2, _3, _4, _5, _6, _7) = (r, r, r, r, r, r, r); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5, out T _6, out T _7, out T _8) => (_1, _2, _3, _4, _5, _6, _7, _8) = (r, r, r, r, r, r, r, r); public void Deconstruct(out T _1, out T _2, out T _3, out T _4,  out T _5, out T _6, out T _7, out T _8, out T _9) => (_1, _2, _3, _4, _5, _6, _7, _8, _9) = (r, r, r, r, r, r, r, r, r); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5, out T _6, out T _7, out T _8, out T _9, out T _10) => (_1, _2, _3, _4, _5, _6, _7, _8, _9, _10) = (r, r, r, r, r, r, r, r, r, r);  public static implicit operator T(Scanner<T> sc) => sc.r; } public static class Input { const char _separator = ' '; static readonly Queue<string> _input = new Queue<string>(); static readonly StreamReader sr =
#if FILE
new StreamReader("in.txt");
#else
new StreamReader(Console.OpenStandardInput());
#endif
public static string ReadLine => sr.ReadLine(); static string ReadStr => Read; static int ReadInt => int.Parse(Read); static long ReadLong => long.Parse(Read); static ulong ReadULong => ulong.Parse(Read); static double ReadDouble => double.Parse(Read); static BigInteger ReadBigInteger => BigInteger.Parse(Read);  public static string Read { get { if (_input.Any()) return _input.Dequeue(); foreach (var val in sr.ReadLine().Split(_separator)) _input.Enqueue(val); return _input.Dequeue(); } }  public static string next() => Read; public static T next<T>() => default(T) switch { sbyte _ => (T) (object) (sbyte) ReadInt, short _ => (T) (object) (short) ReadInt, int _ => (T) (object) ReadInt, long _ => (T) (object) ReadLong, byte _ => (T) (object) (byte) ReadULong, ushort _ => (T) (object) (ushort) ReadULong, uint _ => (T) (object) (uint) ReadULong, ulong _ => (T) (object) ReadULong, float _ => (T) (object) (float) ReadDouble, double _ => (T) (object) ReadDouble, string _ => (T) (object) ReadStr, char _ => (T) (object) ReadStr[0], BigInteger _ => (T) (object) ReadBigInteger, _ => typeof(T) == typeof(string) ? (T) (object) ReadStr : throw new NotSupportedException(), }; public static (T, U) next<T, U>() => (next<T>(), next<U>()); public static (T, U, V) next<T, U, V>() => (next<T>(), next<U>(), next<V>()); public static (T, U, V, W) next<T, U, V, W>() => (next<T>(), next<U>(), next<V>(), next<W>()); public static (T, U, V, W, X) next<T, U, V, W, X>() => (next<T>(), next<U>(), next<V>(), next<W>(), next<X>()); public static T[] nextArray<T>(in int size) { var ret = new T[size]; for (int i = 0; i < size; ++i) ret[i] = next<T>(); return ret; } public static T[,] next2DArray<T>(int n, in int m) { var ret = new T[n, m]; for (int i = 0; i < n; ++i) for (int j = 0; j < n; ++j) ret[i, j] = next<T>(); return ret; } public static (T[], U[]) nextArray<T, U>(in int size) { var ret1 = new T[size]; var ret2 = new U[size]; for (int i = 0; i < size; ++i) (ret1[i], ret2[i]) = next<T, U>(); return (ret1, ret2); } public static (T[], U[], V[]) nextArray<T, U, V>(in int size) { var ret1 = new T[size]; var ret2 = new U[size]; var ret3 = new V[size]; for (int i = 0; i < size; ++i) (ret1[i], ret2[i], ret3[i]) = next<T, U, V>(); return (ret1, ret2, ret3); } } public static class Output { [MethodImpl(256)] public static void print() => Console.WriteLine(); [MethodImpl(256)] public static void print(in string s, bool endline = true) { if (endline) Console.WriteLine(s); else Console.Write(s); } [MethodImpl(256)] public static void print(in char s, bool endline = true) { if (endline) Console.WriteLine(s); else Console.Write(s); } [MethodImpl(256)] public static void print(in int v, bool endline = true) { if (endline) Console.WriteLine(v); else Console.Write(v); } [MethodImpl(256)] public static void print(in long v, bool endline = true) { if (endline) Console.WriteLine(v); else Console.Write(v); } [MethodImpl(256)] public static void print(in ulong v, bool endline = true) { if (endline) Console.WriteLine(v); else Console.Write(v); } [MethodImpl(256)] public static void print(in bool b) => PrintBool(b); [MethodImpl(256)] public static void print(in object v) => Console.WriteLine(v); [MethodImpl(256)] public static void print<T>(in IEnumerable<T> array, string separator = " ") => Console.WriteLine(array.Join(separator)); [MethodImpl(256)] public static void prints<T>(params T[] t) => print(t);
#if LOCAL
[MethodImpl(256)] public static void debug<T>(in T value, bool endline = true) { if (endline) Console.WriteLine(value);else Console.Write(value); }
#else
public static void debug(params object[] obj) { }
#endif
[MethodImpl(256)] static void PrintBool(in bool val, in string yes = null, in string no = null) => print(val ? yes ?? _yes : no ?? _no); static string _yes = "Yes", _no = "No";  public static void SetYesNoString(in YesNoType t) => (_yes, _no) = YesNoString[t]; public static void SetYesNoString(in string yes, in string no) => (_yes, _no) = (yes, no);  static readonly Dictionary<YesNoType, (string yes, string no)> YesNoString = new Dictionary<YesNoType, (string, string)> { {YesNoType.Yes_No, ("Yes", "No")}, {YesNoType.YES_NO, ("YES", "NO")}, {YesNoType.Upper, ("YES", "NO")}, {YesNoType.yes_no, ("yes", "no")}, {YesNoType.Lower, ("yes", "no")}, {YesNoType.Possible_Impossible, ("Possible", "Impossible")}, {YesNoType.Yay, ("Yay!", ":(")}, };  public static readonly (string yes, string no) YN_Possible = ("Possible", "Impossible"), YN_lower = ("yes", "no"), YN_upper = ("YES", "NO"), YN_Yay = ("Yay!", ":(");  public static void Yes() => print(_yes); public static void No() => print(_no);  public static object cout { set => Console.WriteLine(value); }
#if LOCAL
public static object dout { set => Console.WriteLine(value); }
#else
public static object dout { set { } }
#endif
public static object cerr { set => Console.Error.WriteLine(value); }  public const string endl = "\n";  public enum YesNoType { Yes_No, YES_NO, Upper, yes_no, Lower, Possible_Impossible, Yay } } public class Program { public static void Main(string[] args) { var sw = new StreamWriter(Console.OpenStandardOutput()) {AutoFlush = false}; Console.SetOut(sw); new Solver().Main(); Console.Out.Flush(); } } partial class Solver { readonly Scanner<int> Int; readonly Scanner<long> Long; readonly Scanner<string> String; public Solver() => (Int, String, Long) = (new Scanner<int>(), new Scanner<string>(), new Scanner<long>()); const int INF = 1000000010; const long LINF = 1000000000000000100; const double EPS = 1e-9; public static readonly int[] dx = {-1, 0, 0, 1, -1, -1, 1, 1}, dy = {0, 1, -1, 0, -1, 1, -1, 1}; } }namespace Solve.Libraries.ModInt { [DebuggerDisplay("{" + nameof(_value) + "}")] public struct ModInt : IEquatable<ModInt>, IComparable<ModInt> { public const int MOD = 998_244_353;  long _value; public static readonly ModInt Zero = new ModInt(0); public static readonly ModInt One = new ModInt(1); public ModInt(in long value) => _value = (value % MOD + MOD) % MOD; public int Value => (int) _value; public ModInt Invert => ModPow(this, MOD - 2); public static ModInt operator -(ModInt value) { value._value = MOD - value._value; return value; } public static ModInt operator +(ModInt left, in ModInt right) { left._value += right._value; if (left._value >= MOD) left._value -= MOD; return left; } public static ModInt operator -(ModInt left, in ModInt right) { left._value -= right._value; if (left._value < 0) left._value += MOD; return left; } public static ModInt operator *(ModInt left, in ModInt right) => left._value * right._value % MOD; public static ModInt operator /(ModInt left, in ModInt right) => left * right.Invert; public static ModInt operator ++(ModInt value) { if (value._value == MOD - 1) value._value = 0; else value._value++; return value; } public static ModInt operator --(ModInt value) { if (value._value == 0) value._value = MOD - 1; else value._value--; return value; } public static bool operator ==(ModInt left, in ModInt right) => left.Equals(right); public static bool operator !=(ModInt left, in ModInt right) => !left.Equals(right); public static implicit operator ModInt(in int value) => new ModInt(value); public static implicit operator ModInt(in long value) => new ModInt(value); public static explicit operator int(ModInt m) => m.Value; public static ModInt ModPow(ModInt value, long exponent) { var r = new ModInt(1); for (; exponent > 0; value *= value, exponent >>= 1) if ((exponent & 1) == 1) r *= value; return r; } public static ModInt ModFact(int value) { var r = new ModInt(1); for (var i = 2; i <= value; i++) r *= value; return r; } public bool Equals(ModInt other) => _value == other._value; public override bool Equals(object obj) => obj is ModInt m && Equals(m); public override int GetHashCode() => _value.GetHashCode(); public override string ToString() => _value.ToString(); public int CompareTo(ModInt other) => _value.CompareTo(other._value); } }