#include <stdio.h>
typedef int Elemtype;
struct time
{
    Elemtype start;
    Elemtype end;
}mtime[10000];

void Sort(time mtime[],int n);
int Count(time mtime[],int n);
int main()
{
    int n;
    scanf("%d",&n);
    int i = 0;
    for(i=0;i<n;i++)
    {
        scanf("%d%d",&mtime[i].start,&mtime[i].end);
    }
    Sort(mtime,n);
    printf("%d",Count(mtime,n));
    return 0;
}

void Sort(time mtime[],int n)
{
    int i = 0,j=0;
    struct time temp;
    for(i=0;i<n-1;i++)
    {
        for(j=i+1;j<n;j++)
        {
            if(mtime[i].end > mtime[j].end)
            {
                temp = mtime[i];
                mtime[i] = mtime[j];
                mtime[j] = temp;
            }
        }
    }

int Count(time mtime[],int n)
{
    Elemtype s=0;
    int i = 0;
    int num = 1;
    while(i<n)
    {
        s = i;//前一个的结束作为下一个的开始标志
        while((mtime[s].end > mtime[i+1].start) && (i < n))
        {
            i++;
        }
        if(i < n)
        {
            i = i+1;
            num++;
        }
    }
    return num;
}