#include<fstream>
using namespace std;
ifstream fin("zombie.in");
ofstream fout("zombie.out");
long d,k,cost,tot,i,v[1000000],n,m;
int main()
{   fin >> n >> k >> m;
	for (i=1;i<=n;++i)
	{   fin >> v[i];
		d = d + (v[i] - v[i-1]);
	    ++cost;
		if (d >= k)
		{   d = d - k;
		    if (cost >= m)
				tot = tot + m;
			else
				tot = tot + cost;
			cost = 0;
		}
	}
	fout << tot;
	return 0;
}