#include <iostream>
#include <vector>
#include <string>
#include <stack>
#include <algorithm>
#include <bitset>
#include <math.h>
#include <queue>
#include <map>
#include <set>
#include <limits.h>
#include <limits>
#include <stdio.h>
#include <stdlib.h>
#include <sstream>
#include <string.h>
#include <assert.h>
#include <numeric>
using namespace std;

int N, dp[100005];
pair <int, int> country[100005];

vector <int> tree[4 * 100005];
void build(int i, int L, int R){
    if(L == R)tree[i].push_back(country[L].second);
    else{
        int mid = (L + R) >> 1;
        build(2 * i, L, mid);
        build(2 * i + 1, mid + 1, R);

        merge(tree[2 * i].begin(), tree[2 * i].end(), tree[2 * i + 1].begin(), tree[2 * i + 1].end(),
                back_inserter(tree[i]));
    }
}
int query(int i, int L, int R, int s, int t, int k){
    if(t < s)return 0;

    if(s <= L && R <= t){
        return (lower_bound(tree[i].begin(), tree[i].end(), k) - tree[i].begin());
    }else if(R < s || t < L)return 0;
    else{
        int mid = (L + R) >> 1;
        return query(2 * i, L, mid, s, t, k) + query(2 * i + 1, mid + 1, R, s, t, k);
    }
}
int main(){
    scanf("%d", &N);
    for(int i = 0; i < N; i++)
        scanf("%d %d", &country[i].second, &country[i].first);
    sort(country, country + N);

    for(int i = 0; i < (4 * 100005); i++)
        tree[i].clear();
    build(1, 0, N - 1);

    dp[N] = 0;
    for(int x = N - 1; x >= 0; x--){
        int y = max(x + 1, lower_bound(country, country + N, make_pair(country[x].second, 0)) - country);

        dp[x] = 1 + dp[y] + query(1, 0, N - 1, x + 1, y - 1, country[x].first);
        dp[x] = max(dp[x], dp[x + 1]);
    }

    printf("%d\n", dp[0]);
    return 0;
}