#include <bits/stdc++.h>
using namespace std;
const int MOD = (int)1e9 + 7;
const int MOD2 = 1007681537;
const int INF = (int)1e9;
const long long LINF = (long long)1e18;
const long double PI = acos((long double)-1);
const long double EPS = 1e-9;
inline long long gcd(long long a, long long b) {
  long long r;
  while (b) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
inline long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
inline long long fpow(long long n, long long k, int p = MOD) {
  long long r = 1;
  for (; k; k >>= 1) {
    if (k & 1) r = r * n % p;
    n = n * n % p;
  }
  return r;
}
template <class T>
inline int chkmin(T& a, const T& val) {
  return val < a ? a = val, 1 : 0;
}
template <class T>
inline int chkmax(T& a, const T& val) {
  return a < val ? a = val, 1 : 0;
}
inline long long isqrt(long long k) {
  long long r = sqrt(k) + 1;
  while (r * r > k) r--;
  return r;
}
inline long long icbrt(long long k) {
  long long r = cbrt(k) + 1;
  while (r * r * r > k) r--;
  return r;
}
inline void addmod(int& a, int val, int p = MOD) {
  if ((a = (a + val)) >= p) a -= p;
}
inline void submod(int& a, int val, int p = MOD) {
  if ((a = (a - val)) < 0) a += p;
}
inline int mult(int a, int b, int p = MOD) { return (long long)a * b % p; }
inline int inv(int a, int p = MOD) { return fpow(a, p - 2, p); }
inline int sign(long double x) { return x < -EPS ? -1 : x > +EPS; }
inline int sign(long double x, long double y) { return sign(x - y); }
template <class T, T oo>
struct Dinic {
  static const int MAXV = 1e7 + 5;
  static const int MAXE = 1e7 + 5;
  int n, s, t, E;
  int adj[MAXE], nxt[MAXE], lst[MAXV], ptr[MAXV], lev[MAXV], que[MAXV];
  T flw[MAXE], cap[MAXE];
  void init(int n, int s, int t) {
    this->n = n, this->s = s, this->t = t, E = 0;
    fill_n(lst, n, -1);
  }
  void add(int u, int v, T c1, T c2) {
    while (n <= max(u, v)) {
      lst[n++] = -1;
    }
    adj[E] = v, flw[E] = 0, cap[E] = c1, nxt[E] = lst[u], lst[u] = E++;
    adj[E] = u, flw[E] = 0, cap[E] = c2, nxt[E] = lst[v], lst[v] = E++;
  }
  int bfs() {
    fill_n(lev, n, -1), lev[s] = 0;
    int qsize = 0;
    que[qsize++] = s;
    for (int i = 0; i < qsize; i++) {
      for (int u = que[i], e = lst[u]; ~e; e = nxt[e]) {
        int v = adj[e];
        if (flw[e] < cap[e] && !~lev[v]) {
          lev[v] = lev[u] + 1;
          que[qsize++] = v;
        }
      }
    }
    return lev[t] != -1;
  }
  T dfs(int u, T bot) {
    if (u == t) return bot;
    for (int& e = ptr[u]; ~e; e = nxt[e]) {
      int v = adj[e];
      T delta = 0;
      if (lev[v] == lev[u] + 1 && flw[e] < cap[e] &&
          (delta = dfs(v, min(bot, cap[e] - flw[e]))) > 0) {
        flw[e] += delta;
        flw[e ^ 1] -= delta;
        return delta;
      }
    }
    return 0;
  }
  T maxflow() {
    T total = 0;
    while (bfs()) {
      for (int i = 0; i < n; i++) ptr[i] = lst[i];
      for (T delta = dfs(s, oo); delta > 0; delta = dfs(s, oo)) total += delta;
    }
    return total;
  }
};
Dinic<int, (int)1e9> dinic;
const int maxn = 1e6 + 5;
int n, m;
int l[maxn];
int r[maxn];
int tot;
int len[maxn];
struct SegTree {
  int st[maxn << 2];
  void upd(int p, int l, int r, int L, int R, int ix) {
    if (!st[p]) {
      len[p] = R - L + 1;
      st[p] = tot++;
      if (p > 1) {
        dinic.add(st[p >> 1], st[p], R - L + 1, 0);
      }
    }
    if (l > R || r < L) return;
    if (l <= L && r >= R) {
      dinic.add(ix, st[p], 1, 0);
      return;
    }
    upd(p << 1, l, r, L, L + R >> 1, ix);
    upd(p << 1 | 1, l, r, (L + R >> 1) + 1, R, ix);
  }
} seg;
void work(int l, int r, int ix) { seg.upd(1, l, r, 1, m, ix); }
void solve() {
  cin >> n >> m;
  tot = n;
  int s = tot++, t = tot++;
  dinic.init(tot, s, t);
  for (int i = (0); i < (n); i++) {
    dinic.add(s, i, 1, 0);
  }
  for (int i = (0); i < (n); i++) {
    cin >> l[i] >> r[i];
    work(1, l[i], i);
    work(r[i], m, i);
  }
  for (int p = (0); p < (maxn << 2); p++)
    if (seg.st[p] && (!seg.st[p << 1])) {
      dinic.add(seg.st[p], dinic.t, len[p], 0);
    }
  cout << n - dinic.maxflow() << "\n";
}
int main() {
  int JUDGE_ONLINE = 1;
  if (fopen("in.txt", "r")) {
    JUDGE_ONLINE = 0;
    assert(freopen("in.txt", "r", stdin));
  } else {
    ios_base::sync_with_stdio(0), cin.tie(0);
  }
  solve();
  if (!JUDGE_ONLINE) {
  }
  return 0;
}
