#include<fstream> 
using namespace std; 
ifstream in("zombie.in"); 
ofstream out("zombie.out"); 
int main() 
{int d,n,k,total,i,seq_length,seq_start,x;
	in>>d>>n>>k; 
	//initializam 
	in>>seq_start; 
	seq_length=1; // avem deja un prim zombie care intra in strada 
	total=0; 
	d--; 
	for(i=2;i<=n;i++) 
	{
		in>>x; 
		if((x-seq_start)<d)
			seq_length++; 
		else 
		{
			if(seq_length>k) 
				total+=k; 
			else 
				total+=seq_length; 
			seq_start=x; 
			seq_length=1; 
		}
	}
	
	//verificam ultima secventa
	if(seq_length>k) 
		total+=k; 
	else total+=seq_length; 
	
	out<<total; 
}