poj3069

//
//  main.c
//  poj3069
//
//  Created by 韩雪滢 on 11/21/16.
//  Copyright ? 2016 韩雪滢. All rights reserved.
//

#include <stdio.h>
//#include <mm_malloc.h>
#include "malloc.h"
#include <stdlib.h>
#include <time.h>
int R;
int N;
int *points;

int cmp(const void *a,const void *b){
    return *(int*)a<*(int*)b?-1:1;
}

int main(int argc, const char * argv[]) {
    
    while(scanf("%d%d",&R,&N) && R!= -1 && N != -1){
        int i,j;
        int temp = 0;
        int pN = 0;
        points = (int*)malloc(sizeof(int)*N);
        for(i=0;i<N;i++)
            scanf("%d",&points[i]);
        qsort(points,N,sizeof(int),cmp);
        
        while(temp<N-1){
            for(j=temp;j<N;j++)
            {
                if(points[j] > points[temp]+R){
                    temp=j;
                    pN++;
                    break;
                }
            }
        }
        
        printf("%d\n",pN);
    }
    return 0;
}