#include "bits/stdc++.h"
#include<unordered_map>
#include<unordered_set>
#pragma warning(disable:4996)
using namespace std;
using ld = long double;
const ld eps = 1e-9;

//// < "d:\d_download\visual studio 2015\projects\programing_contest_c++\debug\a.txt" > "d:\d_download\visual studio 2015\projects\programing_contest_c++\debug\b.txt"


int main() {
	int N, T; cin >> N >> T;
	vector<int>pluss(T + 1);
	for (int i = 0; i < N; ++i) {
		int l, r; cin >> l >> r;
		pluss[l]++;
		pluss[r]--;
	}
	vector<int>sums(T + 1);
	int ans = 0;
	for (int i = 0; i <= T; ++i) {
		sums[i + 1] = sums[i] + pluss[i];
		ans = max(ans, sums[i + 1]);
	}
	cout << ans << endl;
	return 0;
}