using System; using System.Collections; using System.Collections.Generic; using System.Diagnostics; using System.Globalization; using System.IO; using System.Text; using System.Linq; using E = System.Linq.Enumerable; using System.Threading; internal partial class Solver { public void Run() { var n = ni(); var a = ni(n); Array.Reverse(a); var d = new IndexDictionary(a); var leftNum = new BinaryIndexTree(d.Count); var rightNum = new BinaryIndexTree(d.Count); var leftSum = new BinaryIndexTree(d.Count); var rightSum = new BinaryIndexTree(d.Count); for (int i = 0; i < n; i++) { rightSum.Add(d.IndexOf(a[i]), a[i]); rightNum.Add(d.IndexOf(a[i]), 1); } ModInt.SetMod998244353(); ModInt ans = 0; for (int i = 0; i < n; i++) { var index = d.IndexOf(a[i]); rightNum.Add(index, -1); rightSum.Add(index, -a[i]); ModInt leftN = leftNum.Sum(0, index); ModInt rightN = rightNum.Sum(index + 1, d.Count); ans += leftN * rightN * a[i]; ans += leftSum.Sum(0, index) * rightN; ans += rightSum.Sum(index + 1, d.Count) * leftN; leftNum.Add(index, 1); leftSum.Add(index, a[i]); } cout.WriteLine(ans); } } public class IndexDictionary { private readonly Dictionary _toIndex; private readonly T[] _array; public IndexDictionary(IEnumerable source) : this(source, Comparer.Default.Compare) { } public IndexDictionary(IEnumerable source, Comparison comparison) { _array = source.Distinct().ToArray(); Array.Sort(_array, comparison); _toIndex = new Dictionary(_array.Length); int index = -1; foreach (var x in _array) { _toIndex[x] = ++index; } } public int Count { get { return _array.Length; } } public T this[int index] { get { return _array[index]; } } public int IndexOf(T value) { return _toIndex[value]; } public T[] ToArray() { return _array.ToArray(); } } public class BinaryIndexTree { private readonly long[] array; public BinaryIndexTree(int size) { array = new long[size]; } public long Sum(int begin, int end) { if (begin != 0) { return Sum(0, end) - Sum(0, begin); } long val = 0; end--; for (; end >= 0; end = (end & (end + 1)) - 1) { val += array[end]; } return val; } public void Add(int k, long val) { for (; k < array.Length; k |= k + 1) { array[k] += val; } } /// return min pos where sum(A[0] .. A[pos]) >= w public int LowerBound(long w) { if (w <= 0) { return 0; } int x = 0, k = 1, N = array.Length; while ((k << 1) <= N) { k <<= 1; } for (; k > 0; k >>= 1) { if (x + k - 1 < N && array[x + k - 1] < w) { w -= array[x + k - 1]; x += k; } } return x; } } public partial struct ModInt : IEquatable { private static int mod = 0; private long _value; public ModInt(long x) { _value = x; Normalize(); } private static long RegularMod(long x, int mod) { if (x >= mod) { if (x < 2 * mod) { return x - mod; } return x % mod; } if (x >= 0) { return x; } x = mod - RegularMod(-x, mod); return x == mod ? 0 : x; } public static int SetModValue(int m) { return mod = m; } public static int SetMod998244353() { return SetModValue(998244353); } public static int SetMod1000000007() { return SetModValue(1000000007); } private void Normalize() { _value = RegularMod(_value, mod); } public override string ToString() { return _value.ToString(CultureInfo.InvariantCulture); } public int ToInt() { return (int)_value; } public static bool operator ==(ModInt c1, ModInt c2) { return c1._value == c2._value; } public static bool operator !=(ModInt c1, ModInt c2) { return !(c1 == c2); } public static ModInt operator +(ModInt x, ModInt y) { return new ModInt(x._value + y._value); } public static ModInt operator -(ModInt x, ModInt y) { return new ModInt(x._value - y._value); } public static ModInt operator -(ModInt x) { return new ModInt(-x._value); } public static ModInt operator *(ModInt x, ModInt y) { return new ModInt(x._value * y._value); } public static ModInt operator /(ModInt x, ModInt y) { return new ModInt(x._value * Inverse(y._value, mod)); } public static ModInt operator ++(ModInt x) { return x + 1; } public static ModInt operator --(ModInt x) { return x - 1; } public static ModInt Pow(ModInt x, long n) { ModInt r = 1; while (n > 0) { if ((n & 1) != 0) { r *= x; } x *= x; n >>= 1; } return r; } private static long ExtendedGcd(long a, long b, out long x, out long y) { if (b == 0) { x = 1; y = 0; return a; } else { var d = ExtendedGcd(b, a % b, out y, out x); y -= a / b * x; return d; } } private static long Inverse(long a, long mod) { long x = 0, y = 0; if (ExtendedGcd(a, mod, out x, out y) == 1) { return (x + mod) % mod; } else { throw new Exception("Invalid inverse " + a + " " + mod); } } public static implicit operator ModInt(long x) { return new ModInt(x); } public override bool Equals(object obj) { if (obj == null) { return false; } return _value.Equals(((ModInt)obj)._value); } public override int GetHashCode() { return _value.GetHashCode(); } public bool Equals(ModInt other) { return _value.Equals(other._value); } object ToDump() { return _value; } } // PREWRITEN CODE BEGINS FROM HERE static public class StringExtensions { static public string JoinToString(this IEnumerable source, string separator = " ") { return string.Join(separator, source); } } internal partial class Solver : Scanner { static readonly int? StackSizeInMebiByte = null; //50; public static void StartAndJoin(Action action, int maxStackSize) { var thread = new Thread(new ThreadStart(action), maxStackSize); thread.Start(); thread.Join(); } public static void Main() { #if LOCAL byte[] inputBuffer = new byte[1000000]; var inputStream = Console.OpenStandardInput(inputBuffer.Length); using (var reader = new StreamReader(inputStream, Console.InputEncoding, false, inputBuffer.Length)) { Console.SetIn(reader); new Solver(Console.In, Console.Out).Run(); } #else Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false }); if (StackSizeInMebiByte.HasValue) { StartAndJoin(() => new Solver(Console.In, Console.Out).Run(), StackSizeInMebiByte.Value * 1024 * 1024); } else { new Solver(Console.In, Console.Out).Run(); } Console.Out.Flush(); #endif } #pragma warning disable IDE0052 private readonly TextReader cin; private readonly TextWriter cout; private readonly TextWriter cerr; #pragma warning restore IDE0052 public Solver(TextReader reader, TextWriter writer) : base(reader) { cin = reader; cout = writer; cerr = Console.Error; } public Solver(string input, TextWriter writer) : this(new StringReader(input), writer) { } #pragma warning disable IDE1006 #pragma warning disable IDE0051 private int ni() { return NextInt(); } private int[] ni(int n) { return NextIntArray(n); } private long nl() { return NextLong(); } private long[] nl(int n) { return NextLongArray(n); } private double nd() { return NextDouble(); } private double[] nd(int n) { return NextDoubleArray(n); } private string ns() { return Next(); } private string[] ns(int n) { return NextArray(n); } #pragma warning restore IDE1006 #pragma warning restore IDE0051 } #if DEBUG internal static class LinqPadExtension { public static string TextDump(this T obj) { if (obj is IEnumerable) return (obj as IEnumerable).Cast().JoinToString().Dump(); else return obj.ToString().Dump(); } public static T Dump(this T obj) { return LINQPad.Extensions.Dump(obj); } } #endif public class Scanner { private readonly TextReader Reader; private readonly CultureInfo ci = CultureInfo.InvariantCulture; private readonly char[] buffer = new char[2 * 1024]; private int cursor = 0, length = 0; private string Token; private readonly StringBuilder sb = new StringBuilder(1024); public Scanner() : this(Console.In) { } public Scanner(TextReader reader) { Reader = reader; } public int NextInt() { return checked((int)NextLong()); } public long NextLong() { var s = Next(); long r = 0; int i = 0; bool negative = false; if (s[i] == '-') { negative = true; i++; } for (; i < s.Length; i++) { r = r * 10 + (s[i] - '0'); #if DEBUG if (!char.IsDigit(s[i])) throw new FormatException(); #endif } return negative ? -r : r; } public double NextDouble() { return double.Parse(Next(), ci); } public string[] NextArray(int size) { string[] array = new string[size]; for (int i = 0; i < size; i++) { array[i] = Next(); } return array; } public int[] NextIntArray(int size) { int[] array = new int[size]; for (int i = 0; i < size; i++) { array[i] = NextInt(); } return array; } public long[] NextLongArray(int size) { long[] array = new long[size]; for (int i = 0; i < size; i++) { array[i] = NextLong(); } return array; } public double[] NextDoubleArray(int size) { double[] array = new double[size]; for (int i = 0; i < size; i++) { array[i] = NextDouble(); } return array; } public string Next() { if (Token == null) { if (!StockToken()) { throw new Exception(); } } var token = Token; Token = null; return token; } public bool HasNext() { if (Token != null) { return true; } return StockToken(); } private bool StockToken() { while (true) { sb.Clear(); while (true) { if (cursor >= length) { cursor = 0; if ((length = Reader.Read(buffer, 0, buffer.Length)) <= 0) { break; } } var c = buffer[cursor++]; if (33 <= c && c <= 126) { sb.Append(c); } else { if (sb.Length > 0) break; } } if (sb.Length > 0) { Token = sb.ToString(); return true; } return false; } } }