#include <iostream>
#include <queue>
#include <vector>
#include <atcoder/lazysegtree>
using namespace std;
using ll=long long;
using P=pair<int,int>;
P op(P x,P y){
	return min(x,y);
}
int inf=1e9;
P e(){
	return make_pair(inf,inf);
}
P mapping(int a,P x){
	x.first+=a;
	return x;
}
int composition(int x,int y){
	return x+y;
}
int id(){
	return 0;
}
int main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	int n,k,m;
	cin>>n>>k>>m;
	m--;
	vector<int> a(n);
	for(int i=0;i<n;i++)cin>>a[i];
	vector<int> ans;
	ans.push_back(m);
	for(int i=0;i<n;i++){
		if(i==m)a[i]-=2;
		else a[i]--;
		if(i==m&&a[i]<k){
			cout<<-1<<endl;
			return 0;
		}
	}
	ll sum=0;
	for(int i=0;i<n;i++)sum+=a[i];
	if(sum%(n+1)!=0){
		cout<<-1<<endl;
		return 0;
	}
	sum/=n+1;
	for(int i=0;i<n;i++){
		if(a[i]<sum){
			cout<<-1<<endl;
			return 0;
		}
	}
	atcoder::lazy_segtree<P,op,e,int,mapping,composition,id> seg(n);
	priority_queue<P> pq;
	for(int i=0;i<n;i++){
		if(a[i]<=k+1){
			if(a[i]>sum)pq.push(make_pair(i,a[i]-sum));
		}else{
			seg.set(i,make_pair(a[i]-k-1,i));
		}
	}
	for(int t=0;t<sum;t++){
		while(seg.all_prod().first<1e8){
			auto[x,y]=seg.all_prod();
			if(x==0){
				if(a[y]>sum)pq.push(make_pair(y,a[y]-sum));
				seg.set(y,e());
			}else break;
		}
		if(pq.empty()){
			cout<<-1<<endl;
			return 0;
		}
		auto[x,y]=pq.top();
		pq.pop();
		seg.apply(0,n,-1);
		ans.push_back(x);
		if(y>1)pq.push(make_pair(x,y-1));
	}
	cout<<ans.size()<<endl;
	for(int i=ans.size()-1;i>=0;i--){
		cout<<ans[i]+1;
		if(i>0)cout<<" ";
		else cout<<endl;
	}
}