#include<bits/stdc++.h>
using namespace std;
#define int long long
#define inf 0x3F3F3F3F
const int MXN = 5e5 + 5;
const int LOG = 20;
int n, D, T;
int arr[MXN], L[MXN];
int dp[MXN], ndp[MXN], add[MXN];
int st[MXN << 2], lz[MXN << 2];
void relax(int l, int r, int x)
{
if (!lz[x]) return;
st[x] += lz[x];
if (l != r) lz[2*x] += lz[x], lz[2*x + 1] += lz[x];
lz[x] = 0;
}
void upd(int l, int r, int x, int lx, int rx, int val)
{
if (lx > rx) return;
relax(l, r, x);
if (l > rx || r < lx) return;
if (l >= lx && r <= rx)
{
lz[x] += val;
relax(l, r, x);
return;
}
int mid = (l + r) >> 1;
upd(l, mid, 2*x, lx, rx, val);
upd(mid + 1, r, 2*x + 1, lx, rx, val);
st[x] = min(st[2*x], st[2*x + 1]);
}
int get(int l, int r, int x, int lx, int rx)
{
if (lx > rx) return inf;
if (l > rx || r < lx) return inf;
relax(l, r, x);
if (l >= lx && r <= rx) return st[x];
int mid = (l + r) >> 1;
return min(get(l, mid, 2*x, lx, rx), get(mid + 1, r, 2*x + 1, lx, rx));
}
void make(int ind, int val)
{
upd(0, n, 1, ind, ind, val - get(0, n, 1, ind, ind));
}
void _()
{
cin >> n >> D >> T;
for (int i = 1; i <= n; i++) cin >> arr[i];
{
multiset<array<int, 2>> ms;
multiset<int> mx;
for (int i = 1; i <= n; i++)
{
ms.insert({arr[i] - i, i});
mx.insert(i);
while (!ms.empty() && T - i < (*ms.rbegin())[0])
{
mx.erase(mx.find((*ms.rbegin())[1]));
ms.erase(prev(ms.end()));
}
if (!mx.empty()) L[i] = *mx.rbegin();
}
}
fill(dp + 1, dp + n + 1, inf);
for (int i = 0; i <= D; i++)
{
for (int i = 0; i <= 4 * (n + 1); i++) st[i] = inf, lz[i] = 0;
make(0, 0);
for (int i = 1; i <= n; i++)
{
if (L[i]) upd(0, n, 1, 0, L[i] - 1, 1);
dp[i] = min(dp[i], get(0, n, 1, 0, i - 1));
make(i, dp[i]);
}
}
cout << dp[n] << '\n';
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
while (t--) _();
}
