#ifdef YONIHA
#include <yoniha/all.h>
#else
#include <bits/stdc++.h>
#include <atcoder/all>
#endif
using namespace std;
using namespace atcoder;
#define int long long
#define all(x) (x).begin(), (x).end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rrep(i, n) for(int i = (int)(n - 1); i >= 0; i--)
template <typename T> bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template <typename T> bool chmin(T &a,const T &b){if(a>b){a=b;return true;}return false;}
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vb = vector<bool>;
using vvb = vector<vector<bool>>;
using vs = vector<string>;
using pii = pair<int, int>;
/*
using mint = modint;
using vm = vector<mint>;
using vvm = vector<vector<mint>>;
*/

signed main(){
  int n, h; cin >> n >> h;
  priority_queue<int, vector<int>, greater<>> q;
  while(n--){
  	int a, b; cin >> a >> b;
  	q.emplace(2 * a);
  	q.emplace(2 * b + 1);
  }
  int ans = 0, cnt = 0;
  while(!q.empty()){
  	int t = q.top(); q.pop();
  	if(t % 2) cnt--;
  	else cnt++;
  	chmax(ans, cnt);
  }
  cout << ans << endl;
}