/* vim: set expandtab tabstop=4 shiftwidth=4 : */

import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;

public class Fast
{

    public static void main(String[] args)
    {
        class Solution implements Comparable<Solution>
        {
            private Point[] pts;
            private int n = 0;

            public Solution(int n)
            {
                pts = new Point[n];
            }

            public void add(Point p)
            {
                pts[n++] = p;
            }

            public void sort()
            {
                Insertion.sort(pts);
            }

            public void draw()
            {
                pts[0].drawTo(pts[n - 1]);
            }

            public void print()
            {
                String out = "";
                for (int i = 0; i < n; i++)
                    out += pts[i]+" -> ";
                System.out.println(out.substring(0, (out.length() - 4)));
            }

            public boolean equals(Object o)
            {
                if (o == this) return true;
                if (o == null) return false;
                if (o.getClass() != this.getClass()) return false;

                Solution other = (Solution) o;
                if (n != other.n) return false;

                for (int i = 0; i < n; i++)
                    if (pts[i] != other.pts[i])
                        return false;
                return true;

            }

            public int compareTo(Solution that)
            {
                for (int i = 0; i < n; i++)
                {
                    int r = pts[0].compareTo(that.pts[0]);
                    if (r != 0) return r;
                }
                return 0;
            }
        }

        In in = new In(args[0]);
        int n = in.readInt();

        StdDraw.setXscale(0, 32768);
        StdDraw.setYscale(0, 32768);

        Point[] pts = new Point[n];
        for (int i = 0; i < n; i++)
        {
            pts[i] = new Point(in.readInt(), in.readInt());
        }

        List<Solution> res = new ArrayList<Solution>();
        Point[] others = new Point[n];
        for (int i = 0; i < n; i++)
        {
            Point ref = pts[i];
            ref.draw();
            for (int j = 0; j < n; j++)
                others[j] = pts[j];

            Arrays.sort(others, ref.SLOPE_ORDER);

            int start = 0;
            double slope = Double.NEGATIVE_INFINITY;
            for (int j = 1; j < n; j++)
            {
                double sl = ref.slopeTo(others[j]);
                if (sl == Double.NEGATIVE_INFINITY)
                    continue;

                if (slope != sl)
                {
                    if ((start != 0) && ((j - start) > 2)) {
                        Solution sol = new Solution(j - start + 1);
                        sol.add(ref);
                        for (int k = start; k < j; k++)
                            sol.add(others[k]);
                        sol.sort();
                        if (!res.contains(sol))
                            res.add(sol);
                    }
                    slope = sl;
                    start = j;
                }

            }
            if ((n -  start) > 2) {
                Solution sol = new Solution(n - start + 1);
                sol.add(ref);
                for (int k = start; k < n; k++)
                    sol.add(others[k]);
                sol.sort();
                if (!res.contains(sol))
                    res.add(sol);
            }
        }

        Solution[] sorted = new Solution[res.size()];
        res.toArray(sorted);
        Insertion.sort(sorted);
        for (Solution sol : sorted)
        {
            sol.draw();
            sol.print();
        }
        StdDraw.show(0);
    }
}