class solution{
public static void main(String[]ar){
Scanner in = new Scanner(System.in);
int k=in.nextInt();
int n=in.nextInt();
int ar[]=new int[n];
for(int i=0;i<n;i++){
ar[i]=in.nextInt();
}
int count=1,j=1,l=1,max=0,i;
while(l<n){
i=l;
count=1;
j=i;
while(i<n){
++j;
if(ar[j]-ar[i]>=k){
++count;
i=j;
}
}
if(count>max){
max=count;
}
k++;
}
System.out.println(max);
}
}