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.*;
import static java.lang.Math.*;

public class Main implements Runnable
{
    boolean multiple = false;

    @SuppressWarnings("Duplicates")
    void solve() throws Exception
    {
        long n = sc.nextLong();
        long m = sc.nextLong();
        long k = sc.nextLong();
        PriorityQueue<Long> pq = new PriorityQueue<>();
        for (int i = 0; i < m; i++)
            pq.add(sc.nextLong() - 1L);

        long offset = 0;
        long ans = 0;
        while (!pq.isEmpty())
        {
            long first = pq.poll();
            long removed = 1;
            long trueFirst = first - offset;
            long startPage = (trueFirst / k) * k;

//            System.out.println(first);
//            System.out.println(startPage);
//            System.out.println();

            while (!pq.isEmpty() && pq.peek() - offset < startPage + k)
            {
                pq.poll();
                removed++;
            }

            offset += removed;
            ans++;
        }

        System.out.println(ans);
    }

    long inv(long a, long b)
    {
        return 1 < a ? b - inv(b % a, a) * b / a : 1;
    }

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

    long lcm(long a, long b) { return (a * b) / gcd(a , b); }

    class SegNode
    {
        int max;
        int L, R;
        SegNode left = null, right = null;

        int query(int queryL, int queryR)
        {
            if (queryL == L && queryR == R)
                return max;

            int leftAns = Integer.MIN_VALUE, rightAns = Integer.MIN_VALUE;
            if (left != null && queryL <= left.R)
                leftAns = left.query(queryL, min(queryR, left.R));
            if (right != null && queryR >= right.L)
                rightAns = right.query(max(queryL, right.L), queryR);

            return max(leftAns, rightAns);
        }

        SegNode(int[] arr, int l, int r)
        {
            L = l;
            R = r;
            max = arr[l];

            if (l == r) return;

            int mid = (l + r) / 2;
            left = new SegNode(arr, l, mid);
            right = new SegNode(arr, mid + 1, r);
            max = max(left.max, right.max);
        }
    }

    class Node implements Comparable<Node>
    {
        Node()
        {
        }

        @Override
        public int compareTo(Node o)
        {
            return 0;
        }
    }

    void print(int[] arr)
    {
        for (int i = 0; i < arr.length; i++)
            System.out.print(arr[i] + " ");
        System.out.println();
    }

    @Override
    public void run()
    {
        try
        {
            in = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
            sc = new FastScanner(in);
            if (multiple)
            {
                int q = sc.nextInt();
                for (int i = 0; i < q; i++)
                    solve();
            }
            else
                solve();
        }
        catch (Throwable uncaught)
        {
            Main.uncaught = uncaught;
        }
        finally
        {
            out.close();
        }
    }

    public static void main(String[] args) throws Throwable
    {
        Thread thread = new Thread(null, new Main(), "", (1 << 26));
        thread.start();
        thread.join();
        if (Main.uncaught != null) {
            throw Main.uncaught;
        }
    }

    static Throwable uncaught; BufferedReader in; FastScanner sc; PrintWriter out;
}

class FastScanner
{
    BufferedReader in;
    StringTokenizer st;

    public FastScanner(BufferedReader in)
    {
        this.in = in;
    }

    public String nextToken() throws Exception {
        while (st == null || !st.hasMoreTokens()) {
            st = new StringTokenizer(in.readLine());
        }
        return st.nextToken();
    }

    public int nextInt() throws Exception {
        return Integer.parseInt(nextToken());
    }

    public long nextLong() throws Exception {
        return Long.parseLong(nextToken());
    }

    public double nextDouble() throws Exception {
        return Double.parseDouble(nextToken());
    }
}