#include <bits/stdc++.h>
using namespace std;
const int N = 75000 + 9;
const int INF = (int) 1e9;
int dp[N][18], n, D, T, t[N], segTree[4 * N][18], lazy[4 * N][18], pre[N];
void pushDown (int v, int l, int r, int ID) {
segTree[v][ID] += lazy[v][ID];
if (l == r) {
lazy[v][ID] = 0;
return;
}
lazy[2 * v][ID] += lazy[v][ID];
lazy[2 * v + 1][ID] += lazy[v][ID];
lazy[v][ID] = 0;
return;
}
int getRangeMin (int v, int l, int r, int L, int R, int ID) {
pushDown (v, l, r, ID);
if (L <= l && r <= R)
return segTree[v][ID];
if (l > R || r < L)
return INF;
int mid = (l + r) / 2;
return min (getRangeMin (2 * v, l, mid, L, R, ID), getRangeMin (2 * v + 1, mid + 1, r, L, R, ID));
}
void updateRange (int v, int l, int r, int L, int R, int ID) {
pushDown (v, l, r, ID);
if (L <= l && r <= R) {
lazy[v][ID]++;
pushDown (v, l, r, ID);
return;
}
if (l > R || r < L)
return;
int mid = (l + r) / 2;
updateRange (2 * v, l, mid, L, R, ID);
updateRange (2 * v + 1, mid + 1, r, L, R, ID);
segTree[v][ID] = min (segTree[2 * v][ID], segTree[2 * v + 1][ID]);
return;
}
void updateValue (int v, int l, int r, int idx, int val, int ID) {
pushDown (v, l, r, ID);
if (l == r) {
segTree[v][ID] = val;
return;
}
int mid = (l + r) / 2;
if (l <= idx && idx <= mid)
updateValue (2 * v, l, mid, idx, val, ID);
else updateValue (2 * v + 1, mid + 1, r, idx, val, ID);
segTree[v][ID] = min (segTree[2 * v][ID], segTree[2 * v + 1][ID]);
return;
}
int main () {
cin >> n >> D >> T;
D++;
for (int i = 1; i <= n; i++)
cin >> t[i];
set <int> s;
s.insert (-1);
vector <int> v[n + 2];
for (int i = 1; i <= n; i++) {
v[min(n + 1, max(i + T - t[i] + 1, i))].push_back (i);
s.insert (i);
for (auto u: v[i])
s.erase (u);
pre[i] = *(--s.end());
//cout << pre[i] << ' ';
}
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= D; j++) {
updateRange (1, 0, n, 0, pre[i] - 1, j - 1);
dp[i][j] = getRangeMin (1, 0, n, 0, (j == 1) ? (0) : (i - 1), j - 1);
updateValue (1, 0, n, i, dp[i][j], j);
}
}
//int res = INF;
//for (int i = 0; i <= n; i++)
//res = min (res, dp[i][D]);
cout << dp[n][D] << "\n";
//cout << res << "\n";
}
