#include <bits/stdc++.h>
#define Loop(x,l,r) for (ll x = (l); x < (ll)(r); ++x)
#define LoopR(x,l,r) for (ll x = (r)-1; x >= (ll)(l); --x)
typedef long long ll;
typedef std::pair<int, int> pii;
typedef std::pair<ll , ll > pll;
using namespace std;
const int N = 1<<21;
int a[N];
int n, d, t;
int fen[N];
void fen_add(int i, int x)
{
++i;
while (i < N) {
fen[i] += x;
i += i&-i;
}
}
int fen_get(int r)
{
int ans = 0;
while (r) {
ans += fen[r];
r -= r&-r;
}
return ans;
}
int fen_get(int l, int r) { return fen_get(r) - fen_get(l); }
int l_of[N];
int r_of[N];
int mn_of[N];
int nxt_less[N];
int merge(int l, int m, int r, bool dry)
{
int i = mn_of[l];
int j = min(r, nxt_less[i]);
// t - x == a[i]
int pnt = t - a[i] + 1;
pnt = min(j, pnt);
pnt = max(m, pnt);
int pre_good = fen_get(m, pnt);
if (!dry)
fen_add(m, (pnt - m) - pre_good);
return (pnt - m) - pre_good;
}
int main(int argc, char **argv)
{
cin.tie(0) -> sync_with_stdio(false);
cin >> n >> d >> t;
int lst = 1e9+10;
Loop (i,0,n) {
cin >> a[i];
a[i] -= i;
}
vector<int> st;
LoopR (i,0,n) {
while (st.size() && a[i] < a[st.back()])
st.pop_back();
nxt_less[i] = st.size()? st.back(): n;
st.push_back(i);
}
Loop (i,0,n) {
r_of[i] = i+1;
l_of[i+1] = i;
mn_of[i] = i;
}
l_of[0] = n+1;
r_of[n] = n+1;
l_of[n+1] = n+1;
r_of[n+1] = n+1;
int ans = 0;
Loop (i,0,n) {
int tmp = a[i]+i <= t;
ans += tmp;
fen_add(i, tmp);
}
priority_queue<pair<int, pii>> pq;
Loop (i,1,n) {
int x = merge(i-1, i, i+1, 1);
pq.push({-x, {i-1, i+1}});
}
LoopR (_,d,n-1) {
assert(pq.size());
auto [x, foo] = pq.top();
auto [l, r] = foo;
pq.pop();
x = -x;
int m = r_of[l];
if (m == n+1 || m != l_of[r]) {
++_;
continue;
}
ans += x;
merge(l, m, r, 0);
r_of[l] = r;
l_of[r] = l;
l_of[m] = r_of[m] = n+1;
if (a[mn_of[l]] >= a[mn_of[m]])
mn_of[l] = mn_of[m];
int l2 = l_of[l];
int r2 = r_of[r];
if (l2 != n+1) {
int x = merge(l2, l, r, 1);
pq.push({-x, {l2, r}});
}
if (r2 != n+1) {
int x = merge(l, r, r2, 1);
pq.push({-x, {l, r2}});
}
}
cout << ans << '\n';
}
