#include <bits/stdc++.h>
using namespace std;
long long bin_pow(long long a, long long b) {
  if (b == 0) return 1;
  if (b % 2 == 0) {
    long long t = bin_pow(a, b / 2);
    return t * t % 1000000007;
  } else
    return a * bin_pow(a, b - 1) % 1000000007;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long t = 1, n, m, k = 0, sum = 0, l = 0, r = 0, x = 0, y = 0, z = 0,
            ans = 0, mn = LLONG_MAX, mx = LLONG_MIN;
  string s, s1;
  cin >> n >> m;
  vector<pair<long long, long long> > a;
  for (int i = 0; i < n; i++) {
    cin >> l >> r;
    a.push_back({l, 0});
    a.push_back({r, 1});
  }
  sort(a.begin(), a.end());
  long long lst = 1, cnt = 0;
  vector<long long> c(m + 1);
  for (int i = 0; i < 2 * n - 1; i++) {
    if (a[i].second == 0) {
      cnt++;
      for (int j = a[i].first; j <= a[i + 1].first; j++) c[j] = cnt;
    } else {
      cnt--;
      for (int j = a[i].first + 1; j <= a[i + 1].first; j++) c[j] = cnt;
    }
  }
  vector<long long> d(m + 1, LLONG_MAX), dp(m + 1), d1(m + 1, LLONG_MAX),
      dp1(m + 1);
  d[0] = LLONG_MIN;
  for (int i = 1; i <= m; i++) {
    z = upper_bound(d.begin(), d.end(), c[i]) - d.begin();
    d[z] = c[i];
    dp[i] = z;
  }
  d1[0] = LLONG_MIN;
  for (int i = m; i >= 1; i--) {
    z = upper_bound(d1.begin(), d1.end(), c[i]) - d1.begin();
    d1[z] = c[i];
    dp1[i] = z;
  }
  for (int i = 1; i <= m; i++) {
    ans = max(ans, dp[i] + dp1[i] - 1);
  }
  cout << ans;
  return 0;
}
