10 5 5
2 3 4 5 6
 1 1 1
1
 1000000000000000000 10 68
9818112234872670 233245257111863071 266483628625876079 375103213040049805 431982380866113633 489732004669478331 501030096787260719 541800997319766183 551892546260532408 696178619227890200
 1000000000000000000 2 1
1 1000000000000000000
 33 32 1
1 2 3 4 5 6 7 8 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
 101 55 10
1 3 5 7 8 9 10 16 18 21 22 23 24 25 27 30 32 35 36 37 38 39 40 43 45 47 49 50 51 52 54 57 59 61 64 66 67 68 69 70 71 72 73 80 83 86 87 88 89 90 91 92 96 97 98
 1000000000000000000 5 1000
1 1000000000 1000000000000 1000000000000000 1000000000000001
 15 15 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
 21 21 20
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
 45 43 2
1 2 3 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
 107 20 13
5 9 20 25 26 30 37 45 51 58 62 73 82 87 89 90 99 101 104 106
 3 2 1
1 2
 1000000000 2 1000000000
1 1000000000
 11 7 3
2 3 4 5 6 7 11
 13 9 4
1 2 3 6 7 8 11 12 13
 1000000000000000000 2 1000000000
102306300054748096 267367244641009859
 16 7 5
2 3 4 5 6 15 16
 35 35 1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
 1000000000000000000 20 365
31881893160049984 103938857870698567 103962228223609431 140762820261865064 175962215264653912 239086305245565642 354522451098745823 383839975876242372 443471287955807705 478923027151493682 511195154588214957 619570919279066139 677571312513476877 705864797651447277 789633853044745934 867300890280086078 883297431113041450 891736036124527038 937306858250803630 990892290394455512

2
 1
 10
 2
 32
 15
 4
 1
 2
 35
 9
 2
 1
 4
 4
 2
 4
 35
 20

import java.util.*;
import java.io.*;
public class TokitsukazeAndDiscardItems 
{
	public static void main(String[] args)throws IOException
    {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		PrintWriter pw = new PrintWriter(System.out);
		String S[] = br.readLine().split(" ");
		long N = Long.parseLong(S[0]);
		long M = Long.parseLong(S[1]);
		long K = Long.parseLong(S[2]);
		long ar[] = new long[(int)M];
		S = br.readLine().split(" ");
		LinkedHashMap<Long , LinkedList<Long>> map = new LinkedHashMap<Long , LinkedList<Long>>();
		for(int i = 0 ; i < M ; i += 1)
		{
			ar[i] = Long.parseLong(S[i]);
		}
		Arrays.sort(ar);
		for(int i = 0 ; i < M ; i += 1)
		{
		//	ar[i] = Long.parseLong(S[i]);
			long tmp = (ar[i] % K == 0) ? (ar[i] / K) - 1 : (ar[i] / K);
			LinkedList<Long> list = new LinkedList<Long>();
			if(map.containsKey(tmp))
			{
				list = map.get(tmp);
			}
			list.add(ar[i]);
			map.put(tmp , list);
		}
		boolean flag = false;
		long cnt = 0;
		int len = 0;
		for(Map.Entry<Long , LinkedList<Long>> e : map.entrySet()) 
		{
			int prev = len;
			LinkedList<Long> list = new LinkedList<Long>();
			list = e.getValue();
			long key = e.getKey();
		//	System.out.println(key + " => " + list);
/*			if(key == 0)
			{
				
			}*/
			len = list.size();
			if(len == 0)
			{
				continue;
			}
			if(!flag)
			{
				if(len > 0)
				{
					cnt += 1;
					flag = true;
				}
				continue;	
			}
//			if((list.get(0) % K) <= prev)
			boolean f = false;
		//	System.out.println("prev => " + prev);
			for(Long ll : list)
			{
			//	System.out.println("ele => " + ll);
				if((ll % K) <= prev)
				{
					if(!f)
					{
						cnt += 1;
						f = true;
					}
				}
				if(((ll % K) > prev) || ((ll % K) == 0))
				{
					cnt += 1;
					break;
				}
			}
		}
		pw.println(cnt);
		pw.flush();
		
		
	}
}

