#include <bits/stdc++.h>
using namespace std;
#define modulo 1000000007
#define mod(mod_x) ((((long long)mod_x+modulo))%modulo)
#define Inf 1000000000000000002


int main(){
	
	map<pair<int,int>,int> mp;
	int N;
	cin>>N;

	vector<vector<int>> ind(501,vector<int>(501,-1));
	deque<pair<int,int>> P(N);
	for(int i=0;i<N;i++){
		int X,Y;
		scanf("%d %d",&X,&Y);

		X++;
		Y++;
		ind[X][Y] = i;
		P[i].first=X;
		P[i].second=Y;
	}
	
	sort(P.begin(),P.end());
	
	vector<int> ans;
	while(P.size()!=0){
		if((N+89)/90 <= ans.size())break;
		pair<int,int> T;
		if(P.size()%2==0){
			T = P.back();
			P.pop_back();
		}
		else{
			T = P.front();
			P.pop_front();
		}
		if(ind[T.first][T.second]==-1){
			continue;
		}
		ans.push_back(ind[T.first][T.second]);
		ind[T.first][T.second]=-1;
		int X = T.first;
		int Y = T.second;
		
		for(int i=-10;i<=10;i++){
			for(int j=-10;j<=10;j++){
				if(i*i+j*j<100){
					int x = X+i,y = Y+j;
					if(x<0||y<0||x>500||y>500)continue;
					ind[x][y]=-1;
				}
			}
		}
	}
	
	cout<<ans.size()<<endl;
	for(int i=0;i<ans.size();i++){
		if(i!=0)cout<<' ';
		cout<<ans[i]+1;
	}
	cout<<endl;
		
	
	return 0;
}