#include "parks.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;
typedef long double ld;
#define REP(i,a,b) for(ll i=(ll) a; i<(ll) b; i++)
#define pb push_back
#define mp make_pair
#define pl pair<ll,ll>
#define ff first
#define ss second
#define whole(x) x.begin(),x.end()
#define DEBUG(i) cout<<"DEBUG "<<i<<endl
#define INF 500000000LL
#define EPS 0.00000001
#define pi 3.14159
ll mod=1000000007LL;
int construct_roads(std::vector<int> ax, std::vector<int> ay) {
int n = ax.size();
std::vector<int> u, v, a, b;
int grd[3][100007];
memset(grd, 0, sizeof grd);
for(int i = 0; i < n; i++){
grd[ax[i]/2][ay[i]/2] = i+1;
grd[0][ay[i]/2] += 1<<(ax[i]/2 - 1);
}
bool grp = false;
for(int y = 1; y < 100007; y++){
if(grd[0][y] && !grd[0][y-1] && grp)
return 0;
if(!grd[0][y])
continue;
grp = true;
if(grd[1][y] && grd[1][y-1]){
u.pb(grd[1][y]-1);
v.pb(grd[1][y-1]-1);
a.pb(1);
b.pb(2*y-1);
}
if(grd[2][y] && grd[2][y-1]){
u.pb(grd[2][y]-1);
v.pb(grd[2][y-1]-1);
a.pb(5);
b.pb(2*y-1);
}
if(grd[1][y] && grd[2][y]){
u.pb(grd[1][y]-1);
v.pb(grd[2][y]-1);
a.pb(3);
b.pb(2*y-1);
}
if(grd[0][y] == 1 && grd[0][y-1] == 2)
return 0;
if(grd[0][y] == 2 && grd[0][y-1] == 1)
return 0;
}
build(u, v, a, b);
return 1;
}
