#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define st first
#define nd second
const ll maxn = 500000+912;
vector<vector<int>> dp;
int t[maxn];
int n , D , T;
int ansi = 0;
const int base = (1<<19);
struct node
{
node* l = nullptr;
node* r = nullptr;
int sum = 0;
node (int S){sum = S;}
node (int S , node* L , node* R){sum = S , l = L , r = R;}
};
vector <node*> roots;
node* buduj(int l , int r)
{
if(l == r)
{
return new node(0);
}
int s = (l+r)/2;
return new node(0, buduj(l,s) , buduj(s+1,r));
}
node* U(int l , int r, int a ,int b , node *wsk)
{
if(wsk->sum == (r-l+1) && wsk->l != nullptr)
{
(*(wsk->l)).sum = (r-l+1)/2;
(*(wsk->r)).sum = (r-l+1)/2;
}
if(a <= l && r <= b)
{
return new node((r-l+1) ,wsk->l , wsk->r);
}
else if(r < a || b < l)
{
return wsk;
}
else
{
int s = (l+r)/2;
node* L = U(l,s,a,b,wsk->l);
node* R = U(s+1,r,a,b,wsk->r);
return new node(L->sum+R->sum , L , R);
}
}
int Q(int l , int r, int a ,int b , node* wsk)
{
if(r < a || b < l)return 0;
else if(wsk->sum == (r-l+1))
{
return min(r,b) - max(a,l)+1;
}
else if(a <= l && r <= b)
{
return wsk->sum;
}
else
{
int s = (l+r)/2;
int res = 0;
res += Q(l,s,a,b,wsk->l);
res += Q(s+1,r,a,b,wsk->r);
return res;
}
}
int maxidrz[base*2];
void Up(int X , int val)
{
X += base;
maxidrz[X] = val;
X /= 2;
while(X)
{
maxidrz[X] = max(maxidrz[X*2] , maxidrz[2*X+1]);
X /= 2;
}
}
int Qp(int l , int r)
{
if(r < l)return 0;
int res =0;
l += base;
r += base;
l--;
r++;
while(l/2 != r/2)
{
if((l&1) == 0)res = max(res,maxidrz[l+1]);
if((r&1) == 1)res = max(res,maxidrz[r-1]);
l /= 2;
r /= 2;
}
return res;
}
void rek(int i1 , int i2 , int l , int r , int d)
{
if(i2 < i1)return ;
int i = (i1+i2)/2;
//cerr << i << ' ' << l << ' ' << r << '\n';
dp[i][d] = maxn*10+124;
int COST; // trzeba zupdatowac bo pomijam [i+1,l-1]
ansi = 0;
if(i <= l-2)ansi = Q(0,base-1,i,l-2,roots[(n-i+1)]);
COST = ansi;
//cerr << " " << l << ' ' << COST << ' ' << i << ' ' << l-2 << ' ' << ' ' << t[i] << ' ' << n-i+1 << '\n';
int Pop = 0;
if(i <= l-2) Pop = Qp(i,l-2) - i - (l-2-i+1) + 1; // trzeba zupdatowac bo pomijam [i+1,l-1]
int opt = -1;
for(int j = max(l,i+1) ; j <= r ; j++)
{
Pop--;
Pop = max(Pop,t[j-1]);
if(Pop >= 0)COST++;
if(dp[i][d] > dp[j][d-1] + COST)opt = j;
dp[i][d] = min(dp[i][d] , dp[j][d-1] + COST);
}
rek(i1,i-1,l,opt,d);
rek(i+1,i2,opt,r,d);
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> D >> T;
for(int i = 1; i<= n ;i++)
{
cin >> t[i];
t[i] = T-t[i];
}
roots.push_back(buduj(0,base-1));
for(int i = n ; i >= 1 ;i--)
{
//n <-> 1
//n-1 <-> 2
//...
// n-i <-> i+1 ----> i <-> n-i+1
//cerr << i << ' ' << t[i] << ": " << roots.size() << '\n';
if(t[i] >= 0)
{
//cerr << " " << i << ' ' << i+t[i] << '\n';
roots.push_back(U(0,base-1,i,min(i+t[i],base-1),roots.back()));
}
else
{
roots.push_back((roots.back()));
}
//cerr << " " << roots.back() -> sum << '\n';
Up(i , t[i]+i);
}
dp.resize(n+5);
for(int i = 0 ; i <= n+3 ; i++)dp[i].resize(D+3);
for(int i = 1; i <= n ; i++)dp[i][0] = maxn*123+15;
for(int d = 1 ; d <= D+1 ; d++)
{
rek(1,n,1,n+1,d);
}
cout << dp[1][D+1] << '\n';
return 0;
}
