#include <cstdio>
#include <vector>

using namespace std;

const int maxn=1000005;

long n, k, d, first, sol, i;
vector<long> a(maxn);

int main()
{
    freopen("zombie.in", "r", stdin);
    freopen("zombie.out", "w", stdout);

    scanf("%ld %ld %ld", &d, &n, &k);
    for(i=1; i<=n; ++i) scanf("%ld", &a[i]);

    first=1;
    for(i=2; i<=n; ++i)
    {
        if(a[i]-a[first]>=d)
        {
            if(i-first>=k)
            {
                first=i;
                sol+=k;
            }
            else
            {
                ++first;
                ++sol;
            }
        }
    }

    if(i-first>=k) sol+=k;
    else ++sol;

    printf("%ld\n", sol);

    return 0;
}