Problem:
Score : 500 points

Problem Statement

There are N blocks arranged in a row. Let us paint these blocks.

We will consider two ways to paint the blocks different if and only if there is a block painted in different colors in those two ways.

Find the number of ways to paint the blocks under the following conditions:

For each block, use one of the M colors, Color 1 through Color M, to paint it. It is not mandatory to use all the colors.

There may be at most K pairs of adjacent blocks that are painted in the same color.

Since the count may be enormous, print it modulo 998244353.

Constraints

All values in input are integers.

1 \leq N, M \leq 2 \times 10^5

0 \leq K \leq N - 1

Input

Input is given from Standard Input in the following format:

N M K

Output

Print the answer.

Sample Input 1

3 2 1

Sample Output 1

6

The following ways to paint the blocks satisfy the conditions: 112, 121, 122, 211, 212, and 221. Here, digits represent the colors of the blocks.

Sample Input 2

100 100 0

Sample Output 2

73074801

Sample Input 3

60522 114575 7559

Sample Output 3

479519525

Solution in C# (.NET Core 3.1.201) (judge verdict: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Linq;

namespace contest_Csharp
{
    class Program
    {
        static long power(long a, long b, long modulo)
        {
            long result = 1;
            long buff = a;
            for (long i = 1; i <= b; i *= 2)
            {
                result = result * ((b / i % (2) == 1) ? buff : 1) % modulo;
                buff = (buff * buff) % modulo;
            }
            return result % modulo;
        }
        static long binomal(long n, long r, long modulo)
        {
            long result = 1;
            for (long i = 0; i < r; i++)
            {
                result = (result * (n - i)) % modulo;
                result = (result * power(i+1, modulo - 1, modulo)) % modulo;
            }
            return result;
        }
        static void Main(string[] args)
        {
            var vals = Console.ReadLine().Split(' ')
               .Select(x => long.Parse(x)).ToList();
            var N = vals[0];
            var M = vals[1];
            var K = vals[2];
            long ans = 0;
            long mod = 998244353;
            for (int i = 0; i < K + 1; i++)
            {
                long b = binomal(2, 1, 5);
                ans = (ans +  M*binomal(N-1,i,mod)*power(M - 1, N - i - 1, mod)) % mod;
            }
            Console.WriteLine(ans);


        }



    }
    class PriorityQueue<T> where T : IComparable<T>
    {
        private List<T> heap = new List<T>();
        private int lastindex = -1;
        private void swap(int n, int m)
        {
            T wait = heap[n];
            heap[n] = heap[m];
            heap[m] = wait;
        }
        public int Count()
        {
            return lastindex + 1;
        }
        public void Enqueue(T data)
        {
            int p;
            if (lastindex + 1 < heap.Count())
            {
                heap[lastindex + 1] = data;
            }
            else
            {
                heap.Add(data);
            }
            lastindex++;
            p = lastindex;

            while (true)
            {
                if (p > 0 && heap[p].CompareTo(heap[(p - 1) / 2]) <= -1)
                {
                    swap(p, (p - 1) / 2);
                    p = (p - 1) / 2;
                }
                else
                {
                    break;
                }
            }
        }
        public T Peek()
        {
            return heap[0];
        }
        public T Dequeue()
        {
            T result = Peek();
            heap[0] = default(T);
            swap(0, lastindex);
            lastindex--;
            int p = 0;
            while (true)
            {
                int np;
                if (2 * p + 1 > lastindex)
                {
                    break;
                }
                else
                {
                    np = ((2 * p + 1 == lastindex) || heap[2 * p + 1].CompareTo(heap[2 * p + 2]) <= -1)
                        ? (2 * p + 1) : (2 * p + 2);
                }
                if (heap[p].CompareTo(heap[np]) >= 1)
                {
                    swap(p, np);
                    p = np;
                }
                else
                {
                    break;
                }
            }

            return result;
        }





    }
}