# include <fstream>
using namespace std;
ifstream f ("zombie.in");
ofstream g ("zombie.out");
int a[1000005],k,n,i,j,d,s;
int main ()
{
	f>>d>>n>>k;
	for (i=1;i<=n;i++)
		f>>a[i];
	a[n+1]=1000000001;
	
	i=j=1;
	
	while (j<=n)
	{
		if (a[j+1]-a[i]+1>d)
			if (k<j-i+1)
			{
				s+=k;
				j++;
				i=j;
			}
			else
			{
				s++;
				i++;
			}
		j++;
	}
	if (i<=n)
		if (k<n-i+1)
			s+=k;
		else
			s+=n-i+1;
	g<<s;
	
	return 0;
}