#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define f first
#define s second
#define pii pair<int,int>
#define ppii pair<int,pii>
#define vi vector<int>
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define F(n) for(int i=0;i<n;i++)
#define lb lower_bound
#define ub upper_bound
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
#pragma GCC optimize ("03,unroll-lopps")
#define int long long
using namespace std;
const int mod=1e9+7,mxn=1e6+5,inf=3e18,minf=-3e18,lg=31,Mxn=6e6,base=131;
//#undef int
int n,k,m,q,L,T;
void setIO(string name){
ios_base::sync_with_stdio(0); cin.tie(0);
freopen((name+".in").c_str(),"r",stdin);
freopen((name+".out").c_str(),"w",stdout);
}
vector<pii>point;
int mx[mxn+10];
int ans=0;
bool cmp2(pii a,pii b){
return a.s<b.s;
}
void dnc(int l,int r){
if(l==r)return;
int mid=l+(r-l)/2;
dnc(l,mid);
dnc(mid+1,r);
vector<pii>have;
//x decreasing
//y increasing
vector<pair<pii,int>>ord;
int c1=l,c2=mid+1;
int cnt=0;
while(c2<=r){
while(c1<=mid&&point[c1].s<point[c2].s){
while(have.size()&&have.back().f<point[c1].f){
have.pop_back();
}
have.pb(point[c1]);
ord.pb({point[c1],mx[c1]});
c1++;
}
auto it=lb(all(have),make_pair(0,mx[c2]),cmp2)-have.begin();
ans+=have.size()-it;
if(have.size())mx[c2]=max(mx[c2],have.back().s);
ord.pb({point[c2],mx[c2]});
c2++;
}
while(c1<=mid)ord.pb({point[c1],mx[c1]}),c1++;
for(int i=0;i<ord.size();i++){
point[l+i]=ord[i].f;
mx[l+i]=ord[i].s;
}
}
int32_t main(){
fastio
cin>>n;
for(int i=0;i<n;i++){
int a,b;cin>>a>>b;
point.pb({a,b});
}
sort(all(point));
dnc(0,n-1);
cout<<ans;
}
/*
*/
