#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];
void solve(int l, int r, int lx, int rx)
{
if (l > r) return;
int mid = (l + r) >> 1, cost = 0;
array<int, 2> best = {inf, -1};
for (int i = mid; i >= lx; i--)
{
if (L[i] && L[i] >= lx) add[L[i]]++;
cost += add[i], add[i] = 0;
best = min(best, {cost + dp[i - 1], i});
}
ndp[mid] = best[0];
solve(l, mid - 1, lx, best[1]);
solve(mid + 1, r, best[1], rx);
}
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++)
{
fill(ndp + 1, ndp + n + 1, inf);
solve(1, n, 1, n);
for (int i = 0; i <= n; i++) dp[i] = min(dp[i], ndp[i]);
}
cout << dp[n] << '\n';
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
while (t--) _();
}
