#include<bits/stdc++.h>
#define TASKNAME "codeforce"
#define pb push_back
#define pli pair<int,int>
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
using namespace std;
using ll=int;
const ll maxN=2e6+10;
const ll inf=1e8;
struct node
{
ll pos,val;
node ()
{
val=inf;
pos=0;
}
node operator+(const node&o)
{
node ans;
if(val<=o.val) ans.val=val,ans.pos=pos;
else ans=o;
return ans;
}
};
ll n,a[maxN];
deque<int>dq;
struct IT1
{
node st[4*maxN];
ll lazy[4*maxN];
void build(ll id=1,ll l=1,ll r=n)
{
if(l==r)
{
st[id].val=0;
st[id].pos=l;
return;
}
ll mid=l+r>>1;
build(id*2,l,mid);
build(id*2+1,mid+1,r);
st[id]=st[id*2]+st[id*2+1];
}
void down(ll id)
{
ll &x=lazy[id];
st[id*2].val+=x;
st[id*2+1].val+=x;
lazy[id*2]+=x;
lazy[id*2+1]+=x;
x=0;
}
void update(ll i,ll j,ll val,ll id=1,ll l=1,ll r=n)
{
if(j<l||r<i) return ;
if(i<=l&&r<=j)
{
st[id].val+=val;
lazy[id]+=val;
return;
}
ll mid=l+r>>1;
down(id);
update(i,j,val,id*2+1,mid+1,r);
update(i,j,val,id*2,l,mid);
st[id]=st[id*2]+st[id*2+1];
}
node get()
{
return st[1];
}
}t1;
struct IT2
{
node st[4*maxN];
void update(ll pos,ll val,ll id=1,ll l=1,ll r=n)
{
if(l==r)
{
st[id].val=val;
st[id].pos=l;
return;
}
ll mid=l+r>>1;
if(pos<=mid) update(pos,val,id*2,l,mid);
else update(pos,val,id*2+1,mid+1,r);
st[id]=st[id*2]+st[id*2+1];
}
node get(ll i,ll j,ll id=1,ll l=1,ll r=n)
{
if(j<l||r<i) return node();
if(i<=l&&r<=j) return st[id];
ll mid=l+r>>1;
return get(i,j,id*2,l,mid)+get(i,j,id*2+1,mid+1,r);
}
}t2;
ll t;
ll bs(ll x)
{
ll low=0,high=(ll)dq.size()-1;
while(low<=high)
{
ll mid=low+high>>1;
if(a[dq[mid]]+x<=t) low=mid+1;
else high=mid-1;
}
return high;
}
ll d;
ll l[maxN];
ll ans=0;
void solve()
{
cin >> n >> d >> t;
t1.build();
//t2.build();
for(int i=1;i<=n;i++) cin >>a[i],a[i]-=i;
for(int i=1;i<=n;i++)
{
while(dq.size()>0&&a[i]<=a[dq.back()])
{
dq.pop_back();
}
dq.pb(i);
l[i]=bs(i);
if(l[i]<0) l[i]=i;
else l[i]=dq[l[i]],ans++;
t1.update(l[i]+1,i,-1);
t2.update(i,l[i]+1);
l[i]++;
}
d=min(d,n-1);
//cout << ans << '\n';
while(d--)
{
ans+=t1.get().val;
ll pos=t1.get().pos;
while(true)
{
ll x=t2.get(pos,n).pos;
if(l[x]>pos) break;
t1.update(l[x],x,1);
l[x]=inf;
t2.update(x,l[x]);
}
}
cout << ans;
}
int main()
{
fastio
//freopen(TASKNAME".INP","r",stdin);
//freopen(TASKNAME".OUT","w",stdout);
solve();
}
