#include<cstdio>
#include<vector>
#include<cassert>
#include "books.h"
#define LL long long
using namespace std;
vector<int> ans;
LL a[100010];
void solve(int n,int k,LL c,int s){
	LL now=0,lim=c<<1;
	for(int i=1;i<=k;i++){
		a[i]=skim(i);
		now+=a[i];
	}
	if(now>lim)return impossible();
	if(now>=c){
		for(int i=1;i<=k;i++)ans.push_back(i);
		return answer(ans);
	}
	
	int lf=0,rt=n+1;
	while(lf+1<rt){
		int mid=(lf+rt)>>1;
		a[mid]=skim(mid);
		if(a[mid]>=c)rt=mid;
		else lf=mid;
	}
	
	LL sum=0;
	if(k<rt&&rt<=n){
		sum=a[rt];
		for(int i=1;i<k;i++){
			sum+=a[i];
		}
		if(sum<=lim){
			ans.push_back(rt);
			for(int i=1;i<k;i++)ans.push_back(i);
			return answer(ans);
		}
	}
	
	n=rt-1;
	if(n<k)return impossible();
	for(int i=n;i>=n-k+1;i--){
		a[i]=skim(i);
	}
	
	if((k<<1)>=n){
		for(int i=k+1;i<=n;i++){
//			printf("i=%d now=%lld\n",i,now);
			now=now+a[i]-a[i-k];
			assert(now<=lim);
			if(now>=c){
				for(int j=i-k+1;j<=i;j++)ans.push_back(j);
				return answer(ans);
			}
		}
		return impossible();
	}else{
		for(int i=1;i<=k;i++){
			now=now+a[i+n-k]-a[i];
			assert(now<=lim);
			if(now>=c){
				for(int j=i+1;j<=k;j++)ans.push_back(j);
				for(int j=n-k+1;j<=n-k+i;j++)ans.push_back(j);
				return answer(ans);
			}
		}
		return impossible();
	}
} 


/*

#include<vector>
#include<cstdio>
#include<set>
#include<cstdlib>
#include<cstdarg>
#include<cassert>

using namespace std;

typedef long long ll;

void __attribute__((noreturn)) __attribute__((format(printf, 1, 2))) result(const char *msg, ...)
{
    va_list args;
    va_start(args, msg);
    vfprintf(stderr, msg, args);
    fprintf(stderr, "\n");
    va_end(args);
    exit(0);
}

namespace
{
    int N, K, S, sUsed;
    long long A;
    vector<long long> seq;
}

void impossible()
{
    result("Impossible (not checked): %d book(s) skimmed", sUsed);
    exit(0);
}

long long skim(int pos)
{
    printf("skim(%d): ", pos);
	if (pos<1 || pos>N) result("Invalid skim");
    printf("%lld\n", seq[pos]);
	sUsed++;
	if (sUsed>S) result("Out of books to skim");
    return seq[pos];
}

void answer(vector<int> v)
{
    printf("answer({");
    for(int i = 0; i < (int) v.size(); ++i)
    {
        printf("%d", v[i]);
        if(i + 1 != (int) v.size()) printf(", ");
    }
    printf("})\n");

	if ((int) v.size() != K) result("Invalid answer");
   	ll sum = 0;
	for(auto x: v) {
		if (x<1 || x>N) result("Invalid answer");
		sum += seq[x];
	}	
	if (sum < A || 2*A<sum) result("Wrong answer");

	result("Correct: %d book(s) skimmed", sUsed);
    exit(0);
}

int main()
{
    if(scanf("%d %d %lld %d", &N, &K, &A, &S) != 4)
        result("Invalid input");

    seq.resize(N + 1);
    for(int i = 1; i <= N; ++i) {
    	if(scanf("%lld", &(seq[i])) != 1) result("Invalid input");
		if(i>1 && seq[i]<=seq[i-1]) result("Invalid input");
   	}

    solve(N, K, A, S);

    result("No answer");
}
/*
5 3 10 40
2 3 4 5 6
*/