#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2")
#include<bits/stdc++.h>
using namespace std;

ostream& operator<<(ostream &out, string str) {
    for(char c : str) out << c;
    return out;
}

template<class L, class R> ostream& operator<<(ostream &out, pair<L, R> p) {
    return out << "(" << p.first << ", " << p.second << ")";
}

template<class T> auto operator<<(ostream &out, T a) -> decltype(a.begin(), out) {
    out << "{";
    for(auto it = a.begin(); it != a.end(); it = next(it))
        out << (it != a.begin() ? ", " : "") << *it;
    return out << "}";
}

void dump() { cerr << "\n"; }
template<class T, class... Ts> void dump(T a, Ts... x) {
    cerr << a << ", ";
    dump(x...);
}

#ifdef DEBUG
#  define debug(...) cerr << "[" #__VA_ARGS__ "]: ", dump(__VA_ARGS__)
#else
#  define debug(...) false
#endif

#define REP(i, n) for(int i = 0; i < n; i++)
#define FOR(i, a, b) for(int i = a; i <= b; i++)
#define ST first
#define ND second

template<class T> int size(T && a) { return a.size(); }

using LL = long long;
using PII = pair<int, int>;

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
int rd(int a, int b) { return uniform_int_distribution<int>(a, b)(rng); }

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n;
    cin >> n;
    vector<int> x(n), y(n);
    REP(i, n) cin >> x[i] >> y[i];

    vector<LL> w;
    vector<vector<PII>> e;
    map<LL, int> S;
    map<LL, bool> used;

    REP(i, n) REP(j, n) {
        LL _x = x[i] - x[j];
        LL _y = y[i] - y[j];
        LL d = _x * _x + _y * _y;
        if(S.find(d) == S.end()) {
            S[d] = size(e);
            e.emplace_back();
        }

        int id = S[d];
        e[id].emplace_back(i, j);
        w.emplace_back(d);
    }

    while(true) {
        LL x = w[rd(0, size(w) - 1)];
        while(used[x]) {
            x = w[rd(0, size(w) - 1)];
        }
        used[x] = true;

        vector<vector<int>> graph(n);
        int id = S[x];
        for(PII p : e[id]) {
            int i, j;
            tie(i, j) = p;
            graph[i].emplace_back(j);
            graph[j].emplace_back(i);
        }

        vector<int> col(n, -1);
        bool good = true;
        REP(i, n) {
            if(col[i] == -1) {
                vector<int> Q = {i};
                col[i] = 0;

                while(!Q.empty()) {
                    int v = Q.back();
                    Q.pop_back();

                    for(int u : graph[v]) {
                        if(col[u] == -1) {
                            col[u] = col[v] ^ 1;
                            Q.emplace_back(u);
                        }
                        else if(col[u] == col[v]) {
                            good = false;
                            break;
                        }
                    }

                    if(!good) break;
                }
            }

            if(!good) break;
        }

        if(!good) continue;

        for(auto &v : e) {
            int q = -1;
            for(PII p : v) {
                int x = col[p.ST] ^ col[p.ND];
                if(q == -1) q = x;
                if(q != x) {
                    good = false;
                    break;
                }
            }

            if(!good) break;
        }

        if(!good) continue;

        int cnt = 0;
        REP(i, n) if(col[i]) cnt++;
        cout << cnt << "\n";
        REP(i, n) if(col[i]) cout << i + 1 << " ";
        cout << "\n";
        return 0;
    }
}