#include <bits/stdc++.h>
using namespace std;
long long n, m, k, t, d, p, ans;
int main() {
  cin >> n >> m >> k >> t;
  p = (t - 1) / k;
  for (int i = 1; i < m; ++i) {
    cin >> t;
    if ((t - 1 - d) / k != p) ++ans, d = i, p = (t - 1 - d) / k;
  }
  return cout << ans + 1, 0;
}
