#include<bits/stdc++.h>
using namespace std;
#define MAXN 100003
pair<int,int> Time[MAXN];/*
bool mycmp(const pair<int,int>&a ,const pair<int,int> &b)
{
if(a.second==b.second)
return (a.first<=b.first);
else
return (a.second <=b.second);
}*/
int maxActivities(int n)
{
int i,j,f,c;
f=Time[0].first;
i=1;c=1;
while(i<n)
{
while(i<n && Time[i].second<f)
i++;
if(i==n)
break;
f=Time[i].first;
c++;
i++;
}
return c;
}
int main()
{
int T,n;
int i,j;
scanf("%d",&T);
while(T--)
{
scanf("%d",&n);
for(i=0;i<n;i++)
scanf("%d %d",&(Time[i].second),&(Time[i].first));
// scanf("%d %d",&(Time[i].first),&(Time[i].second));
//sort(Time,Time+n,mycmp);
sort(Time,Time+n);
// printf("max no of activities that can be performed is %d\n",maxActivities(n));
printf("%d\n",maxActivities(n));
}
return 0;
}
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