#include <bits/stdc++.h>
using namespace std;
ifstream f("zombie.in");
ofstream g("zombie.out");
int s,d,n,k;
int main()
{
    f>>d>>n>>k;
    int nr=1,x,y;
    f>>y;
    for(int i=1;i<n;++i)
    {
        f>>x;
        if(x-y>d-1)
        {
            y=x;
            s+=min(k,nr);
            nr=1;
        }
        else
            nr++;
    }
    s+=min(nr,k);
    g<<s;
    return 0;
}