#include<iostream>
#include<cstdio>
#include<stdio.h>
#include<algorithm>
using namespace std;  int i, j, n;int a[1000001], b[1000001];
bool cmp(int x,int y)
{
	return x<y;
}
int main()
{
    scanf("%d", &n);
    for (i = 0; i < n; i++)
    {
        scanf("%d%d", &a[i], &b[i]);
    }
    sort(a, a + n,cmp); sort(b, b + n,cmp);
    int flag = 1, k = 0;
    for (i = 0; i < n; i++)
    {
        if (b[k] <= a[i])
        {
            flag++;
            k = i;
        }
    }
    printf("%d", flag);
    return 0;
}