import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt(), k = sc.nextInt(), d = sc.nextInt();
int[] a = new int[n];
for (int i = 0; i < n; i++) {
a[i] = sc.nextInt();
}
sc.close();
int count = 0;
while (true) {
int max = 0, min = 0, diff;
for (int i = 0; i < n; i++) {
if (a[i] > a[max]) {
max = i;
}
if (a[i] < a[min]) {
min = i;
}
}
if (a[max]-a[min] <= d) {
break;
}
while ((diff = a[max]-a[min]) > d) {
a[max] -= Math.min((diff-d)/2, k);
a[min] += Math.min((diff-d)/2, k);
count++;
}
}
System.out.println(count);
}
}