#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
vector<int> vec[N];
int tr[N << 1];
int lz[N << 1];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  int m;
  cin >> m;
  m += 1;
  auto app = [&](int i, int v) {
    tr[i] += v;
    lz[i] += v;
  };
  auto upd = [&](int l, int r, int v) {
    int L = l += m - 1;
    int R = r += m - 1;
    ++r;
    for (; l < r; l >>= 1, r >>= 1) {
      if (l & 1) app(l++, v);
      if (r & 1) app(--r, v);
    }
    for (; L > 1; L >>= 1) tr[L >> 1] = max(tr[L], tr[L ^ 1]) + lz[L >> 1];
    for (; R > 1; R >>= 1) tr[R >> 1] = max(tr[R], tr[R ^ 1]) + lz[R >> 1];
  };
  for (int i = 0; i < n; ++i) {
    int l;
    cin >> l;
    int r;
    cin >> r;
    vec[l].emplace_back(r);
  }
  int ans = max(0, n - m);
  for (int i = 1; i <= m; ++i) upd(i, i, i - m);
  for (int i = 0; i < m; ++i) {
    for (int r : vec[i]) upd(1, r, 1);
    if (ans < tr[1] - i) ans = tr[1] - i;
  }
  cout << ans << endl;
}
