#include <bits/stdc++.h>
//#include "atcoder/modint"
using namespace std;
typedef long long ll;
const int INF = 1<<30;
const ll INFLL = 1LL<<60;
const ll MOD = 998244353;
const double INFD = 1.0E10;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, -1, 0, 1};
//const int dx[8] = {1, 1, 0, -1, -1, -1, 0, 1};
//const int dy[8] = {0, 1, 1, 1, 0, -1, -1, -1};
using Pair = pair<ll, ll>;
using Graph = vector<set<int>>;
//using mint = atcoder::modint1000000007;d



int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);
    ll n, h; cin >> n >> h;
    vector<ll> cnt(1000002);
    for (int i = 0; i < n; i++){
        ll a, b; cin >> a >> b;
        cnt[a]++; cnt[b + 1]--;
    }
    
    for (int i = 0; i <= 1000000; i++) cnt[i + 1] += cnt[i];
    cout << *max_element(cnt.begin(), cnt.end()) << endl;
        
    
    return 0;
}