#include <stdio.h>
long a1, d, n, k, a, b, rez, i, nr;
int main()
{
	freopen("zombie.in", "r", stdin);
	freopen("zombie.out", "w", stdout);
	scanf("%ld%ld%ld", &d, &n, &k);
	scanf("%ld", &a);
	nr=1;
	a1=a;
	for (i=1; i<n; i++)
	{
		scanf("%ld", &b);
		if (((b-a1)>=d))
		{
			if (nr>k)
				rez+=k;
			else
				rez+=nr;
			nr=1;
			a1=b;
		}//if
		else
			nr++;
		if (i==(n-1))
		{
			if (nr>k)
				rez+=k;
			else
				rez+=nr;
		}//if
		a=b;
	}//for i
	printf("%ld\n", rez);
	return 0;
}//main