#include <bits/stdc++.h>   using namespace std;   void solve() {     long long n, m, k;     cin >> n >> m >> k;     long long p[m];     for (long long int i = 0; i < m; i++) cin >> p[i];     sort(p, p + m);     long long an = 0, x = 0, c = 0, cp = 1;     while (1) {       long long y = x, pg = ceil((long double)(p[x] - x) / (k));       while (y < m && ceil((long double)(p[y] - x) / (k)) == pg) y++;       if (y == m) {         cout << an + 1;         return;       }       an++;       x = y;     }   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     long long TESTS = 1;     while (TESTS--) {       solve();     }     return 0;   }   