#include <iostream>
#include <algorithm>
using namespace std;
#define MAXK 100000
int n, k, d, p[MAXK + 1];
struct BLOCK {
int cost, value;
} b[MAXK + 5]; int bn;
inline bool cmp(BLOCK b1, BLOCK b2) {
if (b1.value != b2.value) return b1.value > b2.value;
return b1.cost < b2.cost;
}
inline bool cmp2(BLOCK b1, BLOCK b2) {
if (b1.value != b2.value) return b1.value > b2.value;
return b1.cost > b2.cost;
}
int res;
void solve() {
int sum = 0, D = d;
for (int i = 1; i <= bn; i++) {
if (b[i].cost <= D) {
D -= b[i].cost;
sum += b[i].value;
}
}
if (res < sum) res = sum;
}
int main() {
cin >> n >> k >> d;
for (int i = 1; i <= k; i++) cin >> p[i];
bn = 0; b[++bn] = { 1, p[1] - 1 }; b[++bn] = { 1, n - p[k] };
for (int i = 2; i <= k; i++) b[++bn] = { 2, p[i] - p[i - 1] - 1 };
sort(b + 1, b + bn + 1, cmp); solve();
bn = 0; b[++bn] = { 1, p[1] - 1 };
for (int i = 2; i <= k; i++) b[++bn] = { 2, p[i] - p[i - 1] - 1 };
sort(b + 1, b + bn + 1, cmp); solve();
bn = 0; b[++bn] = { 1, n - p[k] };
for (int i = 2; i <= k; i++) b[++bn] = { 2, p[i] - p[i - 1] - 1 };
sort(b + 1, b + bn + 1, cmp); solve();
bn = 0;
for (int i = 2; i <= k; i++) b[++bn] = { 2, p[i] - p[i - 1] - 1 };
sort(b + 1, b + bn + 1, cmp); solve();
bn = 0; b[++bn] = { 1, p[1] - 1 }; b[++bn] = { 1, n - p[k] };
for (int i = 2; i <= k; i++) b[++bn] = { 2, p[i] - p[i - 1] - 1 };
sort(b + 1, b + bn + 1, cmp2); solve();
bn = 0; b[++bn] = { 1, p[1] - 1 };
for (int i = 2; i <= k; i++) b[++bn] = { 2, p[i] - p[i - 1] - 1 };
sort(b + 1, b + bn + 1, cmp2); solve();
bn = 0; b[++bn] = { 1, n - p[k] };
for (int i = 2; i <= k; i++) b[++bn] = { 2, p[i] - p[i - 1] - 1 };
sort(b + 1, b + bn + 1, cmp2); solve();
bn = 0;
for (int i = 2; i <= k; i++) b[++bn] = { 2, p[i] - p[i - 1] - 1 };
sort(b + 1, b + bn + 1, cmp2); solve();
cout << res;
}
