#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;

// デバッグ用
#ifndef ONLINE_JUDGE
#define _GLIBCXX_DEBUG
#endif

#define nall(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define YES cout << "Yes\n"
#define NO cout << "No\n"
#define YN {cout << "Yes\n";}else{cout << "No\n";}
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define PRECISION(x) cout << fixed << setprecision(x)
#define endl '\n'
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define each(o, a) for (auto &o : a)

using ll = long long; using ld = long double;
using ull = unsigned long long;
template<typename T> using vc = vector<T>;
template<typename T> using vv = vc<vc<T>>;
using vi = vc<int>; using pii = pair<int, int>; using pll = pair<ll, ll>;
using vl = vc<ll>; using vvl = vv<ll>; using vvvl = vv<vl>;
const int MOD = 998244353;

void solve() {
    ll n, h; cin >> n >> h;
    vl a(n), b(n), table(h+9);
    rep (i, n) {
        cin >> a[i] >> b[i];
        table[a[i]]++;
        table[b[i] + 1]--;
    }
    ll ans = 0, tmp = 0;
    rep (i, h) {
        tmp += table[i];
        chmax(ans, tmp);
    }
    cout << ans << endl;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0; 
}