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
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 1
 2
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 1
 4
 4
 2
 4
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 20

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization("unroll-loops")
using namespace std;
long long max(long long a, long long b) {
  if (a < b) return b;
  return a;
}
long long min(long long a, long long b) {
  if (a < b) return a;
  return b;
}
long long X[] = {-1, 1, 0, 0};
long long Y[] = {0, 0, -1, 1};
long long XX[] = {-1, 1, 0, 0, -1, 1, -1, 1};
long long YY[] = {0, 0, -1, 1, -1, 1, 1, -1};
long long HX[] = {1, -1, 2, -2, 1, -1, -2, 2};
long long HY[] = {2, -2, 1, -1, -2, 2, 1, -1};
long long fpow(long long x, long long n) {
  long long res = 1;
  while (n) {
    if (n & 1) {
      res = res * x % 1000000007;
    }
    x = x * x % 1000000007;
    n >>= 1;
  }
  return (res % 1000000007);
}
long long binomialCoeff(long long n, long long k) {
  long long C[n + 1][k + 1];
  long long i, j;
  C[0][0] = 1;
  for (i = 1; i <= n; i++) {
    for (j = 0; j <= min(i, k); j++) {
      if (j == 0 || j == i)
        C[i][j] = 1;
      else
        C[i][j] = (C[i - 1][j - 1] + C[i - 1][j]) % 1000000007;
    }
  }
  return C[n][k];
}
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long lcm(long long a, long long b) { return a * (b / gcd(a, b)); }
void solve() {
  long long n, m, k;
  cin >> n >> m >> k;
  long long removed = 0;
  long long arr[m], pg[m];
  for (int i = 0; i < m; i++) {
    cin >> arr[i];
    arr[i]--;
    pg[i] = (arr[i] / k);
  }
  long long ind = 0;
  long long step = 0;
  while (1) {
    long long x = (arr[ind] - removed) / k;
    long long add = 0;
    while (ind < m && x == (arr[ind] - removed) / k) {
      ind++;
      add++;
    }
    step++;
    removed += add;
    if (ind >= m) break;
  }
  cout << step;
}
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solve();
}
