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
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 2
 4
 35
 20

import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class C {
	public static void main(String[] args) throws IOException {
		Reader sc = new Reader();
		long n = sc.nextLong(); int m = sc.nextInt(); long k = sc.nextLong();
		long[] p = new long[m + 1];
		for (int i = 0; i < m; i++) {
			p[i] = sc.nextLong();
		}	
		long res = 0;
		for (int i = 0; i < m; ) {
			int j = i;
			//System.out.println(p[i]);
			while (j < m && p[j] < p[i] + k - (p[i] - i - 1) % k) {
				j++;
			}
			i = j;
			res++;
		}
		
		System.out.println(res);
	}


	public static class Reader {
	final private int BUFFER_SIZE = 1 << 16;
	private DataInputStream din;
	private byte[] buffer;
	private int bufferPointer, bytesRead;
	public Reader() {
		din = new DataInputStream(System.in);
		buffer = new byte[BUFFER_SIZE];
		bufferPointer = bytesRead = 0;
	}

	public Reader(String file_name) throws IOException {
		din = new DataInputStream(new FileInputStream(file_name));
		buffer = new byte[BUFFER_SIZE];
		bufferPointer = bytesRead = 0;
	}

	public String readLine() throws IOException {
		byte[] buf = new byte[64]; // line length
		int cnt = 0, c;
		while((c = read()) != -1) {
			if (c == '\n') break;
			buf[cnt++] = (byte) c;
		}
		return new String(buf, 0, cnt);
	}

	public String next() throws IOException {
		byte[] buf = new byte[64]; // word length
		int cnt = 0;
		byte c = read();
		while (c == ' ' || c == '\n')
			c = read();
		do {
			if (c == '\n' || c == ' ') break;
			buf[cnt++] = (byte) c;
		} while((c = read()) != -1);
		return new String(buf, 0, cnt);
	}

	public int nextInt() throws IOException {
		int ret = 0;
		byte c = read();
		while (c <= ' ')
			c = read();
		boolean neg = (c == '-');
		if (neg)
			c = read();
		do {
			ret = ret * 10 + c - '0';
		} while ((c = read()) >= '0' && c <= '9');

		if (neg) 
			return -ret;
		return ret;
	}

	public long nextLong() throws IOException {
		long ret = 0;
		byte c = read();
		while (c <= ' ')
			c = read();
		boolean neg = (c == '-');
		if (neg)
			c = read();
		do {
			ret = ret * 10 + c - '0';
		} while ((c = read()) >= '0' && c <= '9');

		if (neg) 
			return -ret;
		return ret;
	}

	public double nextDouble() throws IOException {
		double ret = 0, div = 1;
		byte c = read();
		while(c <= ' ') c = read();
		boolean neg = (c == '-');
		if (neg) c = read();

		do {
			ret = ret * 10 + c - '0';
		} while ((c = read()) >= '0' && c <= '9');

		if (c == '.') {
			while ((c = read()) >= '0' && c <= '9') {
				ret += (c - '0') / (div *= 10);
			}
		}

		if (neg) return -ret;
		return ret;
	}

	private void fillBuffer() throws IOException {
		bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
		if (bytesRead == -1) buffer[0] = -1;
	}

	private byte read() throws IOException {
		if (bufferPointer == bytesRead) fillBuffer();
		return buffer[bufferPointer++];
	}

	public void close() throws IOException {
		if (din == null) return;
		din.close();
	}

	public static void main(String[] args) throws IOException {
		Reader reader = new Reader();
		System.out.println(reader.next());
		System.out.println(reader.next());
		System.out.println(reader.next());
	}
}
}