//Achen
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<cstdio>
#include<vector>
#include<queue>
#include<ctime>
#include<cmath>
const int N=2e5+7;
typedef long long LL;
using namespace std;
int n,xx[N],yy[N],q1[N],q2[N],top1,top2;
LL ans;template<typename T> void read(T &x) {char ch=getchar(); x=0; T f=1;while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();if(ch=='-') f=-1,ch=getchar();for(;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0'; x*=f;
}struct node{int x,y;friend bool operator <(const node&A,const node &B) {return A.x<B.x;}
}p[N],tp[N];int ef(int x) {int l=1,r=top1,res=0;while(l<=r) {int mid=((l+r)>>1);if(p[q1[mid]].x>x) res=mid,r=mid-1;else l=mid+1;}if(res!=0) res=top1-res+1;return res;
}void cdq(int l,int r) {if(l==r) return; int mid=((l+r)>>1),ql=l-1,qr=mid;top1=top2=0;for(int i=l;i<=r;i++) {if(p[i].y<=mid) {tp[++ql]=p[i];while(top1&&p[q1[top1]].y<p[i].y) top1--;q1[++top1]=i;}else {tp[++qr]=p[i];while(top2&&p[q2[top2]].y>p[i].y) top2--;ans+=ef(p[q2[top2]].x);q2[++top2]=i;}}for(int i=l;i<=r;i++) p[i]=tp[i];cdq(l,mid); cdq(mid+1,r);
}#define DEBUG
int main() {
#ifdef DEBUGfreopen("scarecrows.in","r",stdin);freopen("scarecrows.out","w",stdout);
#endifread(n);for(int i=1;i<=n;i++) {read(p[i].x); read(p[i].y);xx[i]=p[i].x;yy[i]=p[i].y;}sort(xx+1,xx+n+1);sort(yy+1,yy+n+1);for(int i=1;i<=n;i++) {p[i].x=lower_bound(xx+1,xx+n+1,p[i].x)-xx;p[i].y=lower_bound(yy+1,yy+n+1,p[i].y)-yy;}sort(p+1,p+n+1);cdq(1,n);printf("%lld\n",ans);return 0;
}