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 Solution {
	static Scanner sc = new Scanner(System.in);
	static long MAX = (long) (Math.pow(2,32)-1);
	static PrintWriter pw = new PrintWriter(System.out);
	public static void main(String[] args) {
		long n = sc.nextLong();
		int m = sc.nextInt();
		long k = sc.nextLong();
		long arr[] = new long[m];
		for(int i = 0; i < m; i++) {
			arr[i] = sc.nextLong();
		}
		int ans = 0;
		long start = 0;
		for(int i = 0; i< m;) {
			boolean flag  = false;
			start= k + i;
			while(i<m && arr[i]<=start) {
				i++;
				flag = true;
			}
			if(!flag) {
				start = ((arr[i]-start + k-1)/k)*k + start;
				while(i<m && arr[i]<=start) {	
					i++;
				}
			}
			ans++;
			//System.out.println(i +" "+ans);
		}
		System.out.println(ans);
	}
	public static String compare(String s1, String s2) {
		if(s1.length()>s2.length()) {
			return s2;
		}
		else if(s2.length()>s1.length()) {
			return s1;
		}
		else {
			if(s1.compareTo(s2)<0) return s1;
			else return s2;
		}
	}
	public static String sum(String s1, String s2) {
//		System.out.println(s1+" "+s2);
		StringBuilder sb = new StringBuilder();
		StringBuilder temp1 = new StringBuilder(s1);
		StringBuilder temp2 = new StringBuilder(s2);
		s1 = temp1.reverse().toString();
		s2 = temp2.reverse().toString();
//		System.out.println(s1+" "+s2);
		int n = s1.length(), m = s2.length();
		int i = 0, carry = 0;
		while(i<n && i<m) {
			int x = (s1.charAt(i) + s2.charAt(i) - '0' - '0' + carry);
			sb.append(x%10);
			carry = x/10;
			i++;
		}
		while(i<n) {
			int x = (s1.charAt(i) -'0' + carry);
			sb.append(x%10);
			carry = x/10;
			i++;
		}
		while(i<m) {
			int x = (s2.charAt(i) -'0' + carry);
			sb.append(x%10);
			carry = x/10;
			i++;
		}
		if(carry!=0) {
			sb.append(carry);
		}
		return sb.reverse().toString();
	}
}
