#include<fstream>
using namespace std;
ifstream f("zombie.in");
ofstream g("zombie.out");
int i,j,k,p,cost,d,n,a[1000001];
int main()
{f>>d>>n>>k;
for(i=1;i<=n;++i)
	f>>a[i];
i=1;
while(i<=n)
	if(a[k+i]-a[i]>d)
	{++cost;
	++i;
	}
	else
	{p=i;
	cost=cost+k;
	while(a[i+k]-a[p]<=d&&i<=n)
		++i;
	}
g<<cost<<'\n';
f.close();
g.close();
return 0;
}