import java.io.*;
import java.util.*;
public class convention {
	static int[] time = new int[100000];static int N,M,C;
	public static boolean pos(int waittime) {
		int w = 1;
		int fa = time[0];
		int firstpos = 0;// Default
		
		for(int i = 1; i < N;i++) {
			if(time[i] - fa > waittime || (i + 1 - firstpos > C)){
				w += 1;
				fa = time[i];
				firstpos = i;
			}
		}
		return (w