#include <bits/stdc++.h>
#define md ((l + r) >> 1)
using namespace std;
typedef int64_t ll;
int n, m, t;
const int N = 500'005;
struct node {
int lazy;
array<int, 2> mn;
node() {
lazy = 0;
mn = {int(1e9), int(1e9)};
}
node(array<int, 2> _mn) {
lazy = 0;
mn = _mn;
}
friend node operator+(const node &l, const node &r) {
node ret;
ret.mn = min(l.mn, r.mn);
return ret;
}
};
node seg[1 << (__lg(N - 1) + 2)];
void process(int i, int l, int r) {
if (l != r) {
for (auto c : {i << 1, i << 1 | 1}) {
seg[c].lazy += seg[i].lazy;
}
}
seg[i].mn[0] += seg[i].lazy;
seg[i].lazy = 0;
}
void upd(int i, int l, int r, int s, int e, int v) {
process(i, l, r);
if (s <= l && r <= e) {
seg[i].lazy += v;
process(i, l, r);
return;
}
if (r < s || e < l) {
return;
}
upd(i << 1, l, md, s, e, v);
upd(i << 1 | 1, md + 1, r, s, e, v);
seg[i] = seg[i << 1] + seg[i << 1 | 1];
}
void upd2(int i, int l, int r, int x, array<int, 2> v) {
process(i, l, r);
if (l == x && x == r) {
seg[i] = v;
return;
}
if (r < x || x < l) {
return;
}
upd2(i << 1, l, md, x, v);
upd2(i << 1 | 1, md + 1, r, x, v);
seg[i] = seg[i << 1] + seg[i << 1 | 1];
}
node get(int i, int l, int r, int s, int e) {
process(i, l, r);
if (s <= l && r <= e) {
return seg[i];
}
if (r < s || e < l) {
return node();
}
return get(i << 1, l, md, s, e) + get(i << 1 | 1, md + 1, r, s, e);
}
void update(int s, int e, int v) {
if (s > e) return;
upd(1, 0, n - 1, s, e, v);
}
void update(int x, array<int, 2> v) {
if (x < 0) return;
upd2(1, 0, n - 1, x, v);
}
array<int, 2> query(int s, int e) {
return get(1, 0, n - 1, s, e).mn;
}
int a[N];
array<int, 2> dp[N];
array<int, 2> calc(int c) {
for (int i = 0; i < n; i++) {
dp[i] = {int(1e9), int(1e9)};
}
stack<int> s;
dp[n] = {0, 0};
update(n - 1, dp[n]);
s.push(n);
for (int i = n - 1; i >= 0; i--) {
int lst = i;
while (a[i] + s.top() - i <= a[s.top()]) {
int k = s.top();
s.pop();
int eni = t + i - a[i];
int enk = t + k - a[k];
enk++;
if (enk > eni || enk > s.top() - 1 || eni < lst + 1) continue;
eni = max(lst + 1, min(s.top() - 1, eni));
enk = max(lst + 1, min(s.top() - 1, enk));
for (int j = enk; j <= eni; j++) {
update(j, j, j - enk + 1);
}
lst = eni;
update(eni + 1, n - 1, eni - enk + 1);
}
if (a[i] <= t) {
update(i, n - 1, 1);
}
s.push(i);
dp[i] = query(i, n - 1);
dp[i][0] += c, dp[i][1]++;
update(i - 1, dp[i]);
}
return {dp[0][0], dp[0][1]};
}
int dp2[N][2];
int calc2() {
dp[n][0] = 0;
int v[n], cur = 1e9, cnt = 0;
for (int i = 0; i < n; i++) {
cur = min(cur + 1, a[i]);
cnt += (cur <= t);
v[i] = cnt;
}
stack<int> s;
s.push(n);
int ans = 1e9;
for (int i = n - 1; i >= 0; i--) {
int lst = i;
while (a[i] + s.top() - i <= a[s.top()]) {
int k = s.top();
s.pop();
int eni = t + i - a[i];
int enk = t + k - a[k];
enk++;
if (enk > eni || enk > s.top() - 1 || eni < lst + 1) continue;
eni = max(lst + 1, min(s.top() - 1, eni));
enk = max(lst + 1, min(s.top() - 1, enk));
lst = eni;
dp[n][0] += eni - enk + 1;
}
if (a[i] <= t) {
dp[n][0]++;
}
s.push(i);
if (i > 0) ans = min(ans, v[i - 1] + dp[n][0]);
}
return ans;
}
int main() {
ios_base::sync_with_stdio(0), cin.tie(0);
cin >> n >> m >> t;
for (int i = 0; i < n; i++) {
cin >> a[i];
}
a[n] = -1;
if (m == 1) {
cout << calc2() << '\n';
return 0;
}
m++;
int l = 0, r = n;
while (l <= r) {
array<int, 2> v = calc(md);
if (v[1] <= m) {
r = md - 1;
} else {
l = md + 1;
}
}
cout << calc(l)[0] - m * l << '\n';
return 0;
}
