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

#include <bits/stdc++.h>
using namespace std;
struct Tree {
  int l, r, max;
} tree[4 * 100005];
void push_up(int x) {
  tree[x].max = max(tree[x << 1].max, tree[x << 1 | 1].max);
}
void build(int x, int l, int r) {
  tree[x].l = l, tree[x].r = r;
  if (l == r) {
    tree[x].max = 0;
    return;
  }
  int mid = (l + r) >> 1;
  build(x << 1, l, mid);
  build(x << 1 | 1, mid + 1, r);
  push_up(x);
}
void update(int x, int pos, int val) {
  int l = tree[x].l, r = tree[x].r;
  if (l == r) {
    tree[x].max = max(tree[x].max, val);
    return;
  }
  int mid = (l + r) >> 1;
  if (pos <= mid)
    update(x << 1, pos, val);
  else
    update(x << 1 | 1, pos, val);
  push_up(x);
}
int query(int x, int l, int r) {
  int le = tree[x].l, ri = tree[x].r;
  if (l <= le && ri <= r) {
    return tree[x].max;
  }
  int mid = (le + ri) >> 1;
  int maxm = 0;
  if (l <= mid) maxm = max(maxm, query(x << 1, l, r));
  if (r > mid) maxm = max(maxm, query(x << 1 | 1, l, r));
  return maxm;
}
long long n, m, k;
long long p[100005];
int main() {
  cin >> n >> m >> k;
  for (int i = 1; i <= m; i++) cin >> p[i];
  long long t = p[1] / k;
  p[0] = k * t;
  long long sum = 0, ti = 0, res = 1, cnt = 1;
  for (int i = 1; i <= m; i++) {
    if (sum + p[i] - p[i - 1] > k) {
      res++;
      sum += ((p[i] - p[i - 1]) - cnt);
      cnt = 1;
      int f = sum % k == 0 ? 1 : 0;
      sum %= k;
      sum += f;
    } else {
      sum += (p[i] - p[i - 1]);
      cnt++;
    }
  }
  cout << res << endl;
}
