#ifdef LOCAL
#define _GLIBCXX_DEBUG
#endif
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using namespace std;
#define ll long long
#define rep(i,n) for(ll i=0;i<(ll)n;i++)
#define all(v) v.begin(),v.end()
const ll INF = (ll)2e18;

/*
素数判定(エラトステネス)
    下処理O(NloglogN)
    実行O(1)
    pをtureにしp*p以上のpの倍数をfalseに
N以下の自然数がprimeかを表す配列を返す関数
*/
vector<bool> make_is_prime(int N) {
    vector<bool> prime(N + 1, true);
    prime[0] = false;
    prime[1] = false;
    for (int i = 2; i * i <= N; i++) {
        if (!prime[i]) continue;
        for (int j = i * i; j <= N; j += i) {
            prime[j] = false;
        }
    }
    return prime;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    ll N, H;
    cin >> N >> H;
    vector<ll> A(N), B(N);
    vector<ll> memo((ll)1e6 + 10, 0);
    rep(i, N){
        cin >> A[i] >> B[i];
        memo[A[i]]++;
        memo[B[i]+1]--;
    }
    rep(i,(ll)1e6+1){
        memo[i + 1] += memo[i];
    }
    ll MAX = 0;
    rep(i,memo.size()){
        MAX = max(MAX, memo[i]);
    }
    cout << MAX << endl;
}