#include<cstdio>
using namespace std;
int main()
{
	freopen("zombie.in","r",stdin);
	freopen("zombie.out","w",stdout);
	int n,k,j,d,a[1000001],st,nr=1,i;
	long long s=0;
	scanf("%d%d%d",&d,&n,&k);
	for(i=1;i<=n;i++) scanf("%d",&a[i]);
	a[n+1]=-1;
	if (n<=k) printf("%d",n);
	else
	{
		if (n>1)
	{
		st=a[1];
		for(i=2;i<=n;i++)
		{
			if (a[i]+1-st>=d&& a[i]!=-1)
			{
				if (nr<k)
					s=s+nr;
				else s=s+k;
				st=a[i];
				nr=1;
			}
			else nr++;
		}
		if (nr==1)
		{
			if (nr<k)
					s=s+nr;
				else s=s+k;
		}
	}
	}
	printf("%lld",s);
	return 0;
}