#include <fstream>

using namespace std;

const char InFile[]="zombie.in";
const char OutFile[]="zombie.out";
const int MaxN=1000111;

ifstream fin(InFile);
ofstream fout(OutFile);

int D,N,K,sol,V[MaxN];

int main()
{
	fin>>D>>N>>K;--D;
	for(register int i=1;i<=N;++i)
	{
		fin>>V[i];
	}
	fin.close();
	
	int i=1;
	while(i<=N)
	{
		int curr=i;
		++i;
		while(V[i]<=V[curr]+D)
		{
			++i;
		}
		if(i-curr>K)
		{
			sol+=K;
		}
		else
		{
			sol+=(i-curr);
		}
	}


	fout<<sol;
	fout.close();
	return 0;
}