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.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.charset.Charset;
import java.util.Arrays;
import java.util.PriorityQueue;


public class CFContest {
    public static void main(String[] args) throws Exception {
        boolean local = System.getProperty("ONLINE_JUDGE") == null;
        boolean async = false;

        Charset charset = Charset.forName("ascii");

        FastIO io = local ? new FastIO(new FileInputStream("D:\\DATABASE\\TESTCASE\\Code.in"), System.out, charset) : new FastIO(System.in, System.out, charset);
        Task task = new Task(io, new Debug(local));

        if (async) {
            Thread t = new Thread(null, task, "dalt", 1 << 27);
            t.setPriority(Thread.MAX_PRIORITY);
            t.start();
            t.join();
        } else {
            task.run();
        }

        if (local) {
            io.cache.append("\n\n--memory -- \n" + ((Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()) >> 20) + "M");
        }

        io.flush();
    }

    public static class Task implements Runnable {
        final FastIO io;
        final Debug debug;
        int inf = (int) 1e8;

        public Task(FastIO io, Debug debug) {
            this.io = io;
            this.debug = debug;
        }

        @Override
        public void run() {
            solve();
        }

        public void solve() {
            long n = io.readLong();
            int m = io.readInt();
            long k = io.readLong();
            PriorityQueue<Long> queue = new PriorityQueue<>();
            for (int i = 0; i < m; i++) {
                queue.add(io.readLong() - 1);
            }
            int total = 0;
            int discard = 0;
            while (!queue.isEmpty()) {
                int discardNow = 0;
                long page = (queue.peek() - discard) / k;
                while (!queue.isEmpty() && (queue.peek() - discard) / k == page) {
                    queue.poll();
                    discardNow++;
                }
                discard += discardNow;
                total++;
            }

            io.cache.append(total);
        }
    }


    /**
     * 模运算
     */
    public static class Modular {
        int m;

        public Modular(int m) {
            this.m = m;
        }

        public int valueOf(int x) {
            x %= m;
            if (x < 0) {
                x += m;
            }
            return x;
        }

        public int valueOf(long x) {
            x %= m;
            if (x < 0) {
                x += m;
            }
            return (int) x;
        }

        public int mul(int x, int y) {
            return valueOf((long) x * y);
        }

        public int plus(int x, int y) {
            return valueOf(x + y);
        }

        @Override
        public String toString() {
            return "mod " + m;
        }
    }

    public static class BitOperator {
        public int bitAt(int x, int i) {
            return (x >> i) & 1;
        }

        public int bitAt(long x, int i) {
            return (int) ((x >> i) & 1);
        }

        public int setBit(int x, int i, boolean v) {
            if (v) {
                x |= 1 << i;
            } else {
                x &= ~(1 << i);
            }
            return x;
        }

        public long setBit(long x, int i, boolean v) {
            if (v) {
                x |= 1L << i;
            } else {
                x &= ~(1L << i);
            }
            return x;
        }

        /**
         * Determine whether x is subset of y
         */
        public boolean subset(long x, long y) {
            return intersect(x, y) == x;
        }

        /**
         * Merge two set
         */
        public long merge(long x, long y) {
            return x | y;
        }

        public long intersect(long x, long y) {
            return x & y;
        }

        public long differ(long x, long y) {
            return x - intersect(x, y);
        }
    }

    public static class FastIO {
        public final StringBuilder cache = new StringBuilder();
        private final InputStream is;
        private final OutputStream os;
        private final Charset charset;
        private StringBuilder defaultStringBuf = new StringBuilder(1 << 8);
        private byte[] buf = new byte[1 << 13];
        private int bufLen;
        private int bufOffset;
        private int next;

        public FastIO(InputStream is, OutputStream os, Charset charset) {
            this.is = is;
            this.os = os;
            this.charset = charset;
        }

        public FastIO(InputStream is, OutputStream os) {
            this(is, os, Charset.forName("ascii"));
        }

        private int read() {
            while (bufLen == bufOffset) {
                bufOffset = 0;
                try {
                    bufLen = is.read(buf);
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
                if (bufLen == -1) {
                    return -1;
                }
            }
            return buf[bufOffset++];
        }

        public void skipBlank() {
            while (next >= 0 && next <= 32) {
                next = read();
            }
        }

        public int readInt() {
            int sign = 1;

            skipBlank();
            if (next == '+' || next == '-') {
                sign = next == '+' ? 1 : -1;
                next = read();
            }

            int val = 0;
            if (sign == 1) {
                while (next >= '0' && next <= '9') {
                    val = val * 10 + next - '0';
                    next = read();
                }
            } else {
                while (next >= '0' && next <= '9') {
                    val = val * 10 - next + '0';
                    next = read();
                }
            }

            return val;
        }

        public long readLong() {
            int sign = 1;

            skipBlank();
            if (next == '+' || next == '-') {
                sign = next == '+' ? 1 : -1;
                next = read();
            }

            long val = 0;
            if (sign == 1) {
                while (next >= '0' && next <= '9') {
                    val = val * 10 + next - '0';
                    next = read();
                }
            } else {
                while (next >= '0' && next <= '9') {
                    val = val * 10 - next + '0';
                    next = read();
                }
            }

            return val;
        }

        public double readDouble() {
            boolean sign = true;
            skipBlank();
            if (next == '+' || next == '-') {
                sign = next == '+';
                next = read();
            }

            long val = 0;
            while (next >= '0' && next <= '9') {
                val = val * 10 + next - '0';
                next = read();
            }
            if (next != '.') {
                return sign ? val : -val;
            }
            next = read();
            long radix = 1;
            long point = 0;
            while (next >= '0' && next <= '9') {
                point = point * 10 + next - '0';
                radix = radix * 10;
                next = read();
            }
            double result = val + (double) point / radix;
            return sign ? result : -result;
        }

        public String readString(StringBuilder builder) {
            skipBlank();

            while (next > 32) {
                builder.append((char) next);
                next = read();
            }

            return builder.toString();
        }

        public String readString() {
            defaultStringBuf.setLength(0);
            return readString(defaultStringBuf);
        }

        public int readLine(char[] data, int offset) {
            int originalOffset = offset;
            while (next != -1 && next != '\n') {
                data[offset++] = (char) next;
                next = read();
            }
            return offset - originalOffset;
        }

        public int readString(char[] data, int offset) {
            skipBlank();

            int originalOffset = offset;
            while (next > 32) {
                data[offset++] = (char) next;
                next = read();
            }

            return offset - originalOffset;
        }

        public int readString(byte[] data, int offset) {
            skipBlank();

            int originalOffset = offset;
            while (next > 32) {
                data[offset++] = (byte) next;
                next = read();
            }

            return offset - originalOffset;
        }

        public char readChar() {
            skipBlank();
            char c = (char) next;
            next = read();
            return c;
        }

        public void flush() {
            try {
                os.write(cache.toString().getBytes(charset));
                os.flush();
                cache.setLength(0);
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }

        public boolean hasMore() {
            skipBlank();
            return next != -1;
        }
    }

    public static class Debug {
        private boolean allowDebug;

        public Debug(boolean allowDebug) {
            this.allowDebug = allowDebug;
        }

        public void assertTrue(boolean flag) {
            if (!allowDebug) {
                return;
            }
            if (!flag) {
                fail();
            }
        }

        public void fail() {
            throw new RuntimeException();
        }

        public void assertFalse(boolean flag) {
            if (!allowDebug) {
                return;
            }
            if (flag) {
                fail();
            }
        }

        private void outputName(String name) {
            System.out.print(name + " = ");
        }

        public void debug(String name, int x) {
            if (!allowDebug) {
                return;
            }

            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, long x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, double x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, int[] x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.toString(x));
        }

        public void debug(String name, long[] x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.toString(x));
        }

        public void debug(String name, double[] x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.toString(x));
        }

        public void debug(String name, Object x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, Object... x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.deepToString(x));
        }
    }
}