#ifndef GNORT
#include "molecules.h"
#endif
#include <bits/stdc++.h>
#define SQR(x) (1LL * ((x) * (x)))
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(s) (int)s.size()
#define prev __prev
#define next __next
#define left __left
#define right __right
#define mp make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define vi vector<int>
#define vll vector<ll>
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef unsigned int ui;
using namespace std;
const int mod = 1e9 + 7;
const int INF = 1e9 + 7;
const ll INFLL = (ll)2e18 + 7LL;
const ld PI = acos(-1);
const int dx[] = {1, -1, 0, 0, -1, 1, 1, -1};
const int dy[] = {0, 0, 1, -1, -1, -1, 1, 1};
template<class BUI, class TRONG>
bool minimize(BUI &x, const TRONG y){
if(x > y){
x = y;
return true;
} else return false;
}
template<class BUI, class TRONG>
bool maximize(BUI &x, const TRONG y){
if(x < y){
x = y;
return true;
} else return false;
}
/* Author : Bui Nguyen Duc Trong, Luong Van Chanh High School for the gifted*/
/* Template is copied by Trong */
/** Losing in Provincial Contests **/
/** TRYING HARDER**/
/** ORZ **/
/* -----------------[ MAIN CODE GOES HERE ]----------------- */
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
vector<int> find_subset(int l, int u, vector<int> w){
vector<int> ans;
int n = sz(w);
vector<pair<ll, int>> val(n);
for(int i = 0; i < n; i++) val[i] = mp(w[i], i);
sort(all(val));
for(int i = 1; i < n; i++) val[i].fi += val[i - 1].fi;
auto getRange = [&](int l, int r) -> ll{
if(l == 0) return val[r].fi;
return val[r].fi - val[l - 1].fi;
};
for(int i = 0; i < n; i++){
int lo = 0, hi = i, p = -1;
while(lo <= hi){
int mid = (lo + hi) >> 1;
if(getRange(mid, i) >= l){
p = mid;
lo = mid + 1;
} else hi = mid - 1;
}
if(p != -1 && getRange(p, i) <= u){
for(int j = p; j <= i; j++) ans.push_back(val[j].se);
break;
}
}
return ans;
}
/*
4 15 17
6 8 8 7
*/
#ifdef GNORT
void solve(){
int n, l, u; cin >> n >> l >> u;
vector<int> w(n);
for(int i = 0; i < n; i++) cin >> w[i];
vector<int> ans = find_subset(l, u, w);
cout << sz(ans) << ": ";
for(int x : ans) cout << x << ' '; cout << '\n';
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
const bool multitest = 0;
int tt = 1; if(multitest) cin >> tt;
while( tt-- ){
solve();
}
return 0;
}
#endif
