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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.util.TreeMap;

public class Main1 {

	static FastReader input = new FastReader();
	static PrintWriter out = new PrintWriter(System.out);
	static long n, k;
	static int m;
	static long[] a;
	static TreeMap<Long, Long> shift;

	public static void main(String[] args) throws IOException {

		n = input.nextLong();
		m = input.nextInt();
		k = input.nextLong();

		a = new long[m];
		shift = new TreeMap<>();

		for (int i = 0; i < m; i++)
			a[i] = input.nextLong();

		int oper = 0;

		long os = 0;
		long curs = 0;

		for (int i = 0; i < m;) {

			long pos = (a[i] - os) / k;

			pos = (a[i] - os) % k != 0 ? pos + 1 : pos;

			int j = i;

			while (true) {
				long part = (a[j] - os) / k;
				part = (a[j] - os) % k != 0 ? part + 1 : part;
				if (j < a.length && part <= pos) {
					j++;
					curs = os + j - i;
				}
				if (j >= a.length || part > pos)
					break;
			}
			os = curs;
			i = j;
			oper++;
		}
		out.println(oper);
		out.flush();
	}

	static class FastReader {
		BufferedReader br;
		StringTokenizer st;

		public FastReader() {
			br = new BufferedReader(new InputStreamReader(System.in));
		}

		String next() throws IOException {
			while (st == null || !st.hasMoreElements()) {
				st = new StringTokenizer(br.readLine());
			}
			return st.nextToken();
		}

		int nextInt() throws NumberFormatException, IOException {
			return Integer.parseInt(next());
		}

		long nextLong() throws NumberFormatException, IOException {
			return Long.parseLong(next());
		}

		double nextDouble() throws NumberFormatException, IOException {
			return Double.parseDouble(next());
		}

		String nextLine() throws IOException {
			String str = "";
			str = br.readLine();
			return str;
		}
	}

	static class con {
		static int IINF = (int) 1e9;
		static int _IINF = (int) -1e9;
		static long LINF = (long) 1e15;
		static long _LINF = (long) -1e15;
		static double EPS = 1e-9;
	}

	static class Triple implements Comparable<Triple> {
		int x;
		int y;
		int z;

		Triple(int x, int y, int z) {
			this.x = x;
			this.y = y;
			this.z = z;
		}

		@Override
		public int compareTo(Triple o) {
			if (x == o.x && y == o.y)
				return z - o.z;
			if (x == o.x)
				return y - o.y;
			return x - o.x;
		}
	}

	static class Pair implements Comparable<Pair> {
		int x;
		int y;

		Pair(int x, int y) {
			this.x = x;
			this.y = y;

		}

		@Override
		public int compareTo(Pair o) {
			if (x == o.x)
				return y - o.y;
			return x - o.x;
		}
	}

	static void shuffle(int[] a) {
		for (int i = 0; i < a.length; i++) {
			int r = i + (int) (Math.random() * (a.length - i));
			int tmp = a[r];
			a[r] = a[i];
			a[i] = tmp;
		}
	}

	static int gcd(int a, int b) {
		return b == 0 ? a : gcd(b, a % b);
	}

}