import java.util.*;
import java.io.*;
import java.lang.*;
class Activity
{
int start;
int finish;
Activity(int s, int f)
{
start = s;
finish = f;
}
}
class MyCmp implements Comparator<Activity>
{
public int compare(Activity a1, Activity a2)
{
return a1.finish - a2.finish;
}
}
class GFG
{
static int maxActivity(Activity arr[], int n)
{
Arrays.sort(arr, new MyCmp());
int res = 1;
int prev = 0;
for(int curr = 1; curr < n; curr++)
{
if(arr[curr].start >= arr[prev].finish)
{
res++;
prev = curr;
}
}
return res;
}
public static void main(String args[])
{
Activity arr[] = {new Activity(12, 25),
new Activity(10, 20),
new Activity(20, 30)};
int n = 3;
System.out.println(maxActivity(arr, n));
}
}