#include <cstdio>
#include <cstring>
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

const int maxn=100010;
typedef long long ll;
int n,mx,my;
ll ans;
int xl[maxn],xr[maxn],yl[maxn],yr[maxn],s[maxn];
struct point
{
	int x,y;
}p[maxn];
struct node
{
	int val,org;
}num[maxn];
vector<int> q1[maxn],q2[maxn];
vector<int>::iterator it;
bool cmpv(const node &a,const node &b)
{
	return a.val<b.val;
}
bool cmpx(const point &a,const point &b)
{
	return a.x<b.x;
}
inline void updata(int x,int val)
{
	for(int i=x;i<=mx;i+=i&-i)	s[i]+=val;
}
inline int query(int x)
{
	int i,ret=0;
	for(i=x;i;i-=i&-i)	ret+=s[i];
	return ret;
}
inline int rd()
{
	int ret=0,f=1;	char gc=getchar();
	while(gc<‘0‘||gc>‘9‘)	{if(gc==‘-‘)	f=-f;	gc=getchar();}
	while(gc>=‘0‘&&gc<=‘9‘)	ret=ret*10+(gc^‘0‘),gc=getchar();
	return ret*f;
}
int main()
{
	n=rd();
	int i;
	for(i=1;i<=n;i++)	num[i].val=rd(),p[i].y=rd(),num[i].org=i;
	sort(num+1,num+n+1,cmpv);
	for(i=1;i<=n;i++)
	{
		if(i==1||num[i].val>num[i-1].val)	mx++;
		p[num[i].org].x=mx;
	}
	for(i=1;i<=n;i++)	num[i].val=p[i].y,num[i].org=i;
	sort(num+1,num+n+1,cmpv);
	for(i=1;i<=n;i++)
	{
		if(i==1||num[i].val>num[i-1].val)	my++;
		p[num[i].org].y=my;
	}
	memset(xl,0x3f,sizeof(xl)),memset(yl,0x3f,sizeof(yl));
	for(i=1;i<=n;i++)
	{
		xr[p[i].x]=max(xr[p[i].x],p[i].y),xl[p[i].x]=min(xl[p[i].x],p[i].y);
		yr[p[i].y]=max(yr[p[i].y],p[i].x),yl[p[i].y]=min(yl[p[i].y],p[i].x);
	}
	for(i=1;i<=mx;i++)	q1[xl[i]].push_back(i),q2[xr[i]].push_back(i);
	for(i=1;i<=my;i++)
	{
		for(it=q1[i].begin();it!=q1[i].end();it++)	updata(*it,1);
		ans+=query(yr[i])-query(yl[i]-1);
		for(it=q2[i].begin();it!=q2[i].end();it++)	updata(*it,-1);
	}
	printf("%lld",ans);
	return 0;
}