#include <bits/stdc++.h>
#include "books.h"
using namespace std;
#pragma GCC optimize("O3")
#define endl '\n'
#define db double
#define ll long long
#define pb push_back
#define fs first
#define sd second
#define Mod long(1e9 + 7)
#define all(x) x.begin(), x.end()
#define unvisited long(-1)
#define Eps double(1e-9)
#define _for(i, n) for(int i = 0; i < (n); i++)
#define dbg(x) cout << #x ": " << x << endl;
const ll Inf = 1e18;
//
// --- Sample implementation for the task books ---
//
// To compile this program with the sample grader, place:
// books.h books_sample.cpp sample_grader.cpp
// in a single folder and run:
// g++ books_sample.cpp sample_grader.cpp
// in this folder.
//
bool check(ll sum, ll a){
return (sum >= a && sum <= 2*a);
}
pair<int, int> find(vector <ll> v, ll x, ll y){
int n = v.size()-1, l = n+1, r = 0;
vector <pair<ll, ll>> s(n+2, { 0, Inf });
for(int i = 1; i <= n; i++){
s[i].fs = s[i-1].fs;
if(v[i] != -1){
s[i].fs = v[i];
}
}
for(int i = n; i >= 1; i--){
s[i].sd = s[i-1].sd;
if(v[i] != -1){
s[i].sd = v[i];
}
}
for(int i = 1; i <= n; i++){
if(y >= s[i].fs && s[i].sd >= x){
l = min(l, i);
r = max(r, i);
}
}
return { l, r+1 };
}
void solve(int n, int k, long long a, int s)
{
vector <ll> v(n+1, -1);
vector <int> ans;
ll sum = 0;
for(int i = 1; i <= k; i++){
v[i] = skim(i);
ans.push_back(i);
sum += v[i];
}
if(sum > 2*a){
impossible();
return;
}else if(check(sum, a)){
answer(ans);
return;
}
int last = n+1;
for(auto& u : ans)
{
pair <int, int> t = find(v, v[u]+1, 2*a-sum+v[u]);
int l = max(t.fs, k+1), r = min(t.sd, last);
if(l > r) break;
while (abs(l - r) != 1)
{
int mid = (l + r) / 2;
if(v[mid] == -1){
v[mid] = skim(mid);
}
ll tmp = sum + (v[mid] - v[0]);
if(tmp >= sum && tmp <= 2*a)
l = mid;
else
r = mid;
}
if(v[l] > v[u]){
sum = sum + (v[l] - v[u]);
u = l;
last = u;
}
}
if(check(sum, a))
answer(ans);
else
impossible();
}
