using System;
using System.Linq;
using System.Collections.Generic;
using static System.Console;
using System.Text;
using System.IO;
using static System.Math;
using System.Numerics;

namespace AtCoder
{
    public class Program
    {
        public static void Main(string[] args)
        {
            //SetOut(new StreamWriter(OpenStandardOutput()) { AutoFlush = false });
            Solve();
            //Out.Flush();
            Read();
        }

        static void Solve()
        {
            var (N, C) = Slice2<long>();
            var schc = Enumerable.Repeat(0, (int)C).Select(_ => new List<(long s, long t)>()).ToArray();
            for (var i = 0; i < N; ++i)
            {
                var (s, t, c) = Slice3<long>();
                schc[c - 1].Add((s, t));
            }
            var sch = new List<(long s, long t)>();
            for (var i = 0; i < C; ++i)
            {
                schc[i].Sort();
                schc[i].Add((long.MaxValue, long.MaxValue));
                for (var j = 0; j < schc[i].Count - 1; ++j)
                {
                    var s = schc[i][j];
                    while (true)
                    {
                        var ns = schc[i][j + 1];
                        if (s.t != ns.s) break;
                        s.t = ns.t;
                        ++j;
                    }
                    sch.Add((s.s - 1, s.t));
                }
            }
            sch.Sort();
            var cnt = 1L;
            var pq = new priority_queue<long>((l, r) => r.CompareTo(l));
            pq.insert(sch[0].t);
            for (var i = 1; i < sch.Count; ++i)
            {
                var s = sch[i];
                if (pq.top() <= s.s)
                    pq.extract();
                pq.insert(s.t);
                cnt = Max(cnt, pq.num);
            }
            WriteLine(cnt);
        }
        class priority_queue<T>
        {
            Comparison<T> cmp;
            T[] A = new T[2000000];
            // var pq = new priority_queue<long>((l, r) => l.CompareTo(r));
            // とすれば値の大きいものから優先
            public priority_queue(Comparison<T> c)
            {
                cmp = c;
            }
            public int num { get; private set; } = 0;
            public T top() => A[0];
            public void insert(T v)
            {
                A[num] = v;
                ++num;
                increaseKey(num);
            }
            void increaseKey(int i)
            {
                while (1 < i && 0 < cmp(A[i - 1], A[i / 2 - 1]))
                {
                    var t = A[i - 1];
                    A[i - 1] = A[i / 2 - 1];
                    A[i / 2 - 1] = t;
                    i = i / 2;
                }
            }
            public T extract()
            {
                if (num < 1) return default(T);
                var max = A[0];
                A[0] = A[num - 1];
                --num;
                maxHeapify(1);
                return max;
            }
            void maxHeapify(int i)
            {
                var H = num;
                var l = left(i);
                var r = right(i);
                var largest = 0;
                if (l <= H && 0 < cmp(A[l - 1], A[i - 1])) { largest = l; } else { largest = i; }
                if (r <= H && 0 < cmp(A[r - 1], A[largest - 1])) { largest = r; }
                if (largest != i)
                {
                    var t = A[i - 1];
                    A[i - 1] = A[largest - 1];
                    A[largest - 1] = t;
                    maxHeapify(largest);
                }
            }
            int left(int l) => l * 2;
            int right(int r) => r * 2 + 1;
        }

        static long Mod = (long)1e9 + 7;
        static public long[] Sarray() { return ReadLine().Split().Select(long.Parse).ToArray(); }
        static public List<long> Slist() { return ReadLine().Split().Select(long.Parse).ToList(); }
        static public (T1 a, T2 b) Slice<T1, T2>()
        {
            var t = ReadLine().Split();
            return (
            (T1)Convert.ChangeType(t[0], typeof(T1)),
            (T2)Convert.ChangeType(t[1], typeof(T2)));
        }
        static public (T a, T b) Slice2<T>()
        {
            var t = ReadLine().Split();
            return (
            (T)Convert.ChangeType(t[0], typeof(T)),
            (T)Convert.ChangeType(t[1], typeof(T)));
        }
        static public (T a, T b, T c) Slice3<T>()
        {
            var t = ReadLine().Split();
            return (
            (T)Convert.ChangeType(t[0], typeof(T)),
            (T)Convert.ChangeType(t[1], typeof(T)),
            (T)Convert.ChangeType(t[2], typeof(T)));
        }
    }
}

Measured memory_bytes: 51960