#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define int long long
#define rnd(l, r) uniform_int_distribution<int>(l, r)(rng)
using namespace std;
void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
int pow(int a,int b,int m){int ans=1;while(b){if(b&1){ans=(ans*a)%m;}b>>=1;a=(a*a)%m;}return ans;}
int binpow(int a,int b){int ans=1;while(b){if(b&1){ans=(ans*a);}b>>=1;a=(a*a);}return ans;}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 1e5 + 100, mxc = 105, inf = 1e18, MX = 1e5 + 10;
int dx[8] = {1, 0, 0, -1, 1, 1, -1, -1};
int dy[8] = {0, 1, -1, 0, 1, -1, 1, -1};
int x[N], y[N];
map <pair <int,int>, int> mp;
main(){
iostream::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int t, n;
cin >> n >> t;
for(int i = 1; i <= n; i++){
cin >> x[i] >> y[i];
mp[{x[i], y[i]}] = i;
}
int f = 1;
for(int i = 1; i <= n; i++){
if(x[f] > x[i])f = i;
}
set <pair <int, int> > st;
st.insert({x[f], f});
vector <int> was(n + 1);
vector <int> ans;
while(!st.empty()){
int ind = st.begin() -> ss;
ans.pb(ind);
was[ind] = 1;
st.erase(st.begin());
for(int i = 0; i < 8; i++){
if(mp.count({x[ind] + dx[i], y[ind] + dy[i]})){
if(was[mp[{x[ind] + dx[i], y[ind] + dy[i]}]] == 1)continue;
st.insert({x[ind] + dx[i], mp[{x[ind] + dx[i], y[ind] + dy[i]}]});
}
}
}
if(ans.size() != n){
cout << "NO\n";
return 0;
}
cout << ans.size() << endl;
for(auto x : ans)
cout << x <<" ";
}
/*
* Before implementing the problem:
Do I understand the problem correctly?
Which places are tricky? What do I need to remember to implement them correctly?
Which place is the heaviest by implementation? Can I do it simpler?
Which place is the slowest? Where do I need to be careful about constant factors and where I can choose slower but simpler implementation?
----------------------------------
If not AC:
Did you remember to do everything to handle the tricky places you thought about before?
Is the solution correct?
Do I understand the problem correctly?
----------------------------------
If you have a test on which the solution gives wrong answer:
Is the solution doing what it was supposed to do?
Is the problem in the code or in the idea?
*/
