#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define MOD 9001
 
using namespace std;
typedef long long ll;

int d, n, k, a[1001000], cnt;
ll rs = 0;
 
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
 
    ifstream cin("zombie.in");
    ofstream cout("zombie.out");
    
    cin >> d >> n >> k;
    int last = 0;
    for (int i = 1, x; i <= n; i++, cnt++) {
        cin >> x;
        if (x - last >= d) {
            rs += min(k, cnt);
            cnt = 1;
            last = x;
        }
    }

    cout << rs + min(k, cnt);
	return 0;
}