#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
template <class T>
using pq = priority_queue<T>;
template <class T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
int scan() { return getchar(); }
void scan(int &a) { cin >> a; }
void scan(long long &a) { cin >> a; }
void scan(char &a) { cin >> a; }
void scan(double &a) { cin >> a; }
void scan(long double &a) { cin >> a; }
void scan(char a[]) { scanf("%s", a); }
void scan(string &a) { cin >> a; }
template <class T>
void scan(vector<T> &);
template <class T, size_t size>
void scan(array<T, size> &);
template <class T, class L>
void scan(pair<T, L> &);
template <class T, size_t size>
void scan(T (&)[size]);
template <class T>
void scan(vector<T> &a) {
  for (auto &i : a) scan(i);
}
template <class T>
void scan(deque<T> &a) {
  for (auto &i : a) scan(i);
}
template <class T, size_t size>
void scan(array<T, size> &a) {
  for (auto &i : a) scan(i);
}
template <class T, class L>
void scan(pair<T, L> &p) {
  scan(p.first);
  scan(p.second);
}
template <class T, size_t size>
void scan(T (&a)[size]) {
  for (auto &i : a) scan(i);
}
template <class T>
void scan(T &a) {
  cin >> a;
}
void IN() {}
template <class Head, class... Tail>
void IN(Head &head, Tail &...tail) {
  scan(head);
  IN(tail...);
}
string stin() {
  string s;
  cin >> s;
  return s;
}
template <class T>
inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
vector<int> iota(int n) {
  vector<int> a(n);
  iota(begin(a), end(a), 0);
  return a;
}
template <class T>
void UNIQUE(vector<T> &x) {
  sort(begin(x), end(x));
  x.erase(unique(begin(x), end(x)), x.end());
}
int in() {
  int x;
  cin >> x;
  return x;
}
long long lin() {
  unsigned long long x;
  cin >> x;
  return x;
}
void print() { putchar(' '); }
void print(bool a) { cout << a; }
void print(int a) { cout << a; }
void print(long long a) { cout << a; }
void print(char a) { cout << a; }
void print(string &a) { cout << a; }
void print(double a) { cout << a; }
template <class T>
void print(const vector<T> &);
template <class T, size_t size>
void print(const array<T, size> &);
template <class T, class L>
void print(const pair<T, L> &p);
template <class T, size_t size>
void print(const T (&)[size]);
template <class T>
void print(const vector<T> &a) {
  if (a.empty()) return;
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    cout << " ";
    print(*i);
  }
  cout << endl;
}
template <class T>
void print(const deque<T> &a) {
  if (a.empty()) return;
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    cout << " ";
    print(*i);
  }
}
template <class T, size_t size>
void print(const array<T, size> &a) {
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    cout << " ";
    print(*i);
  }
}
template <class T, class L>
void print(const pair<T, L> &p) {
  cout << '(';
  print(p.first);
  cout << ",";
  print(p.second);
  cout << ')';
}
template <class T>
void print(set<T> &x) {
  for (auto e : x) print(e), cout << " ";
  cout << endl;
}
template <class T, size_t size>
void print(const T (&a)[size]) {
  print(a[0]);
  for (auto i = a; ++i != end(a);) {
    cout << " ";
    print(*i);
  }
}
template <class T>
void print(const T &a) {
  cout << a;
}
int out() {
  putchar('\n');
  return 0;
}
template <class T>
int out(const T &t) {
  print(t);
  putchar('\n');
  return 0;
}
template <class Head, class... Tail>
int out(const Head &head, const Tail &...tail) {
  print(head);
  putchar(' ');
  out(tail...);
  return 0;
}
long long gcd(long long a, long long b) {
  while (b) {
    long long c = b;
    b = a % b;
    a = c;
  }
  return a;
}
long long lcm(long long a, long long b) {
  if (!a || !b) return 0;
  return a * b / gcd(a, b);
}
vector<pair<long long, long long>> factor(long long x) {
  vector<pair<long long, long long>> ans;
  for (long long i = 2; i * i <= x; i++)
    if (x % i == 0) {
      ans.push_back({i, 1});
      while ((x /= i) % i == 0) ans.back().second++;
    }
  if (x != 1) ans.push_back({x, 1});
  return ans;
}
vector<int> divisor(int x) {
  vector<int> ans;
  for (int i = 1; i * i <= x; i++)
    if (x % i == 0) {
      ans.push_back(i);
      if (i * i != x) ans.push_back(x / i);
    }
  return ans;
}
int popcount(long long x) { return __builtin_popcountll(x); }
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int n) { return uniform_int_distribution<int>(0, n - 1)(rng); }
template <class... T>
void err(const T &...) {}
template <class Monoid, class OperatorMonoid = Monoid>
struct RandomizedBinarySearchTree {
  using F = function<Monoid(Monoid, Monoid)>;
  using G = function<Monoid(Monoid, OperatorMonoid)>;
  using H = function<OperatorMonoid(OperatorMonoid, OperatorMonoid)>;
  using P = function<OperatorMonoid(OperatorMonoid, int)>;
  inline int xor128() {
    static int x = 123456789;
    static int y = 362436069;
    static int z = 521288629;
    static int w = 88675123;
    int t;
    t = x ^ (x << 11);
    x = y;
    y = z;
    z = w;
    return w = (w ^ (w >> 19)) ^ (t ^ (t >> 8));
  }
  struct Node {
    Node *l, *r;
    int cnt;
    Monoid key, sum;
    OperatorMonoid lazy;
    Node() = default;
    Node(const Monoid &k, const OperatorMonoid &p)
        : cnt(1), key(k), sum(k), lazy(p), l(nullptr), r(nullptr) {}
  };
  vector<Node> pool;
  int ptr;
  const Monoid M1;
  const OperatorMonoid OM0;
  const F f;
  const G g;
  const H h;
  const P p;
  RandomizedBinarySearchTree(int sz, const F &f, const Monoid &M1)
      : pool(sz),
        ptr(0),
        f(f),
        g(G()),
        h(H()),
        p(P()),
        M1(M1),
        OM0(OperatorMonoid()) {}
  RandomizedBinarySearchTree(int sz, const F &f, const G &g, const H &h,
                             const P &p, const Monoid &M1,
                             const OperatorMonoid &OM0)
      : pool(sz), ptr(0), f(f), g(g), h(h), p(p), M1(M1), OM0(OM0) {}
  inline Node *alloc(const Monoid &key) {
    return &(pool[ptr++] = Node(key, OM0));
  }
  virtual Node *clone(Node *t) { return t; }
  inline int count(const Node *t) { return t ? t->cnt : 0; }
  inline Monoid sum(const Node *t) { return t ? t->sum : M1; }
  inline Node *update(Node *t) {
    t->cnt = count(t->l) + count(t->r) + 1;
    t->sum = f(f(sum(t->l), t->key), sum(t->r));
    return t;
  }
  Node *propagate(Node *t) {
    t = clone(t);
    if (t->lazy != OM0) {
      t->key = g(t->key, p(t->lazy, 1));
      if (t->l) {
        t->l = clone(t->l);
        t->l->lazy = h(t->l->lazy, t->lazy);
        t->l->sum = g(t->l->sum, p(t->lazy, count(t->l)));
      }
      if (t->r) {
        t->r = clone(t->r);
        t->r->lazy = h(t->r->lazy, t->lazy);
        t->r->sum = g(t->r->sum, p(t->lazy, count(t->r)));
      }
      t->lazy = OM0;
    }
    return update(t);
  }
  Node *merge(Node *l, Node *r) {
    if (!l || !r) return l ? l : r;
    if (xor128() % (l->cnt + r->cnt) < l->cnt) {
      l = propagate(l);
      l->r = merge(l->r, r);
      return update(l);
    } else {
      r = propagate(r);
      r->l = merge(l, r->l);
      return update(r);
    }
  }
  pair<Node *, Node *> split(Node *t, int k) {
    if (!t) return {t, t};
    t = propagate(t);
    if (k <= count(t->l)) {
      auto s = split(t->l, k);
      t->l = s.second;
      return {s.first, update(t)};
    } else {
      auto s = split(t->r, k - count(t->l) - 1);
      t->r = s.first;
      return {update(t), s.second};
    }
  }
  Node *build(int l, int r, const vector<Monoid> &v) {
    if (l + 1 >= r) return alloc(v[l]);
    return merge(build(l, (l + r) >> 1, v), build((l + r) >> 1, r, v));
  }
  Node *build(const vector<Monoid> &v) {
    ptr = 0;
    return build(0, (int)v.size(), v);
  }
  void dump(Node *r, typename vector<Monoid>::iterator &it) {
    if (!r) return;
    r = propagate(r);
    dump(r->l, it);
    *it = r->key;
    dump(r->r, ++it);
  }
  vector<Monoid> dump(Node *r) {
    vector<Monoid> v((size_t)count(r));
    auto it = begin(v);
    dump(r, it);
    return v;
  }
  string to_string(Node *r) {
    auto s = dump(r);
    string ret;
    for (int i = 0; i < s.size(); i++) ret += ", ";
    return (ret);
  }
  void insert(Node *&t, int k, const Monoid &v) {
    auto x = split(t, k);
    t = merge(merge(x.first, alloc(v)), x.second);
  }
  void erase(Node *&t, int k) {
    auto x = split(t, k);
    t = merge(x.first, split(x.second, 1).second);
  }
  Monoid query(Node *&t, int a, int b) {
    auto x = split(t, a);
    auto y = split(x.second, b - a);
    auto ret = sum(y.first);
    t = merge(x.first, merge(y.first, y.second));
    return ret;
  }
  void set_propagate(Node *&t, int a, int b, const OperatorMonoid &p) {
    if (b <= a) return;
    auto x = split(t, a);
    auto y = split(x.second, b - a);
    y.first->lazy = h(y.first->lazy, p);
    t = merge(x.first, merge(propagate(y.first), y.second));
  }
  void set_element(Node *&t, int k, const Monoid &x) {
    t = propagate(t);
    if (k < count(t->l))
      set_element(t->l, k, x);
    else if (k == count(t->l))
      t->key = t->sum = x;
    else
      set_element(t->r, k - count(t->l) - 1, x);
    t = update(t);
  }
  int size(Node *t) { return count(t); }
  bool empty(Node *t) { return !t; }
  Node *makeset() { return nullptr; }
  int lower_bound(Node *t, const Monoid &x) {
    if (!t) return 0;
    t = propagate(t);
    if (x <= t->key) return lower_bound(t->l, x);
    return lower_bound(t->r, x) + count(t->l) + 1;
  }
  pair<int, Monoid> lower_bound_with_value(Node *t, const Monoid &x) {
    if (!t) return {0, M1};
    t = propagate(t);
    if (x <= t->key) {
      auto res = lower_bound_with_value(t->l, x);
      if (t->key <= x) return {res.first, f(res.second, t->key)};
      return res;
    }
    auto res = lower_bound_with_value(t->r, x);
    res.first += count(t->l) + 1;
    return {res.first, f(res.second, t->key)};
  }
  Monoid kth(Node *t, int n) {
    t = propagate(t);
    if (!t) return M1;
    if (n <= count(t->l)) return kth(t->l, n);
    if (n == count(t->l) + 1) return t->key;
    return kth(t->r, n - count(t->l) - 1);
  }
};
signed main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  cout << fixed << setprecision(15);
  int n;
  IN(n);
  auto f = [](int x, int y) { return max(x, y); };
  auto p = [](int x, int y) { return x; };
  const int N = 1e6;
  RandomizedBinarySearchTree<int> tree(N, f, plus<int>(), plus<int>(), p, 0, 0);
  RandomizedBinarySearchTree<int>::Node *root = nullptr;
  tree.insert(root, 0, 0);
  for (long long i = 0; i < n; ++i) {
    int l = in(), r = in();
    int a = tree.lower_bound(root, l), b = tree.lower_bound(root, r);
    tree.set_propagate(root, a, b, 1);
    tree.erase(root, b);
    tree.insert(root, a, l);
  }
  cout << tree.count(root) - 1 << '\n';
}
