using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using static System.Math;
using static System.Array;
using static AtCoder.Tool;

namespace AtCoder
{
    class AC
    {
        const int MOD = 1000000007;
        const int INF = int.MaxValue / 2;
        const long SINF = long.MaxValue / 2;
        const double EPS = 1e-8;
        static readonly int[] dx = { 0, 1, 0, -1 };
        static readonly int[] dy = { 1, 0, -1, 0 };
        //static List<List<int>> G = new List<List<int>>();
        //static List<List<Edge>>G = new List<List<Edge>>();
        //static List<Edge> E = new List<Edge>();

        

        static void Main(string[] args)
        {
            //var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            //Console.SetOut(sw);
            var cin = new Scanner();
            var input = cin.SplitRead();
            int N = input[0];
            int K = input[1];
            var x = new long[N];
            var y = new long[N];

            for(var i = 0; i < N; i++)
            {
                var p = cin.SplitReadL();
                x[i] = p[0];
                y[i] = p[1];
            }
            long ans = SINF;

            if (K == 2)
            {
                
                for(var i = 0; i < N - 1; i++)
                {
                    for(var j = i + 1; j < N; j++)
                    {

                        ans = Min(ans, Abs((x[i] - x[j]) * (y[i] - y[j])));
                    }
                }
                Console.WriteLine(ans);
                return;
            }
            if (K == 3)
            {
                
                for(var i = 0; i < N - 2; i++)
                {
                    for(var j = i + 1; j < N - 1; j++)
                    {
                        for(var k = j + 1; k < N; k++)
                        {
                            var Xmax = MaxLot(x[i], x[j], x[k]);
                            var Xmin = MinLot(x[i], x[j], x[k]);

                            var Ymax = MaxLot(y[i], y[j], y[k]);
                            var Ymin = MinLot(y[i], y[j], y[k]);

                            ans = Min(ans, (Xmax - Xmin) * (Ymax - Ymin));

                        }
                    }
                }
                Console.WriteLine(ans);
                return;
            }

            
            for(var a = 0; a < N - 3; a++)
            {
                for(var b = a + 1; b < N - 2; b++)
                {
                    for(var c = b + 1; c < N - 1; c++)
                    {
                        for(var d = c + 1; d < N; d++)
                        {
                            var Xmax = MaxLot(x[a], x[b], x[c], x[d]);
                            var Xmin = MinLot(x[a], x[b], x[c], x[d]);

                            var Ymax = MaxLot(y[a], y[b], y[c], y[d]);
                            var Ymin = MinLot(y[a], y[b], y[c], y[d]);

                            var S = (Xmax - Xmin) * (Ymax - Ymin);

                            int cnt = 0;
                            for(var i = 0; i < N; i++)
                            {
                                if (Xmin <= x[i] && x[i] <= Xmax && Ymin <= y[i] && y[i] <= Ymax)
                                {
                                    cnt++;
                                }
                            }
                            if (cnt >= K)
                            {
                                ans = Min(ans, S);
                            }
                        }
                    }
                }
            }

            Console.WriteLine(ans);
            

            //Console.Out.Flush();
        }
        
        
        struct Edge
        {
            public int from;

            public int to;
            public long dist;
            public Edge(int t, long c)
            {
                from = -1;
                to = t;
                dist = c;
            }
            public Edge(int f, int t, long c)
            {
                from = f;
                to = t;
                dist = c;
            }

        }
        struct Pair<T, U> : IComparable<Pair<T, U>>
        where T : IComparable<T>
        where U : IComparable<U>
        {
            public T first;
            public U second;
            private readonly bool CompWithFirst;

            public Pair(T f, U s, int comp)
            {
                first = f;
                second = s;
                CompWithFirst = comp == 1;
            }
            public Pair(T f,U s)
            {
                first = f;
                second = s;
                CompWithFirst = true;
            }

            public int CompareTo(Pair<T, U> other)
            {
                return CompWithFirst ? first.CompareTo(other.first) : second.CompareTo(other.second);
            }
        }
    }
    public class PriorityQueue<T> where T : IComparable<T>
    {

        private List<T> Q;
        private readonly int r;

        public PriorityQueue(bool ascending)
        {
            if (ascending)
            {
                r = 1;
            }
            else
            {
                r = -1;
            }
            Q = new List<T>();
        }


        private void PushHeap(List<T> list, T item)
        {
            int n = list.Count();
            list.Add(item);

            while (n != 0)
            {
                int pIndex = (n - 1) / 2;

                if (list[n].CompareTo(list[pIndex]) * r > 0)
                {
                    Swap(Q, n, pIndex);
                }
                else { break; }

                n = pIndex;
            }
        }

        private void PopHeap(List<T> list)
        {
            int n = list.Count() - 1;
            list[0] = list[n];
            list.RemoveAt(n);

            int cur = 0;
            int comp;

            while (2 * cur + 1 <= n - 1)
            {
                int c1 = 2 * cur + 1;
                int c2 = 2 * (cur + 1);
                if (c1 == n - 1)
                {
                    comp = c1;
                }
                else
                {

                    comp = list[c1].CompareTo(list[c2]) * r > 0 ? c1 : c2;
                }

                if (list[cur].CompareTo(list[comp]) * r < 0)
                {
                    Swap(Q, cur, comp);
                }
                else { break; }

                cur = comp;
            }
        }

        private void Swap(List<T> list, int a, int b)
        {
            T keep = list[a];
            list[a] = list[b];
            list[b] = keep;
        }



        public void Enqueue(T value)
        {
            PushHeap(Q, value);
        }

        public T Dequeue()
        {
            T ret = Q[0];
            PopHeap(Q);
            return ret;
        }

        public T Peek()
        {
            return Q[0];
        }

        public int CountItem()
        {
            return Q.Count();
        }
    }
    public class Scanner
    {
        public int[] SplitRead()
        {
            int[] array = Console.ReadLine().Split().Select(int.Parse).ToArray();
            return array;
        }
        public long[] SplitReadL()
        {
            long[] array = Console.ReadLine().Split().Select(long.Parse).ToArray();
            return array;
        }
    }
    public static class Tool
    {
        static public void Initialize<T>(ref T[] array, T initialvalue)
        {
            for (var i = 0; i < array.Length; i++)
            {
                array[i] = initialvalue;
            }
        }

        static public T MaxLot<T>(params T[] val) where T : IComparable<T>
        {
            T ret = val[0];
            for (var i = 1; i < val.Count(); i++)
            {
                if (ret.CompareTo(val[i]) < 0) { ret = val[i]; }
            }
            return ret;
        }
        static public T MinLot<T>(params T[] val) where T : IComparable<T>
        {
            T ret = val[0];
            for (var i = 1; i < val.Count(); i++)
            {
                if (ret.CompareTo(val[i]) > 0) { ret = val[i]; }
            }
            return ret;
        }
    }

}


Measured memory_bytes: 17480