//2022tysc0819
#include<bits/stdc++.h>
using namespace std;
#define int long long
//#define double long double
//#define map unordered_map
//#pragma GCC optimize(2,3,"Ofast","inline")
const int N=5e5+10,M=1010,P=998244353,MOD=998244353;
const double PI=3.1415926,EPS=0.00001;
int n,l,cnt;
struct line{int l,r;}a[N];
bool cmp(line x,line y){
    if(x.l!=y.l)return x.l<y.l;
    return x.r<y.r;
}
signed main(){
    cin>>n;
    for(int i=1;i<=n;i++){cin>>a[i].l>>a[i].r;}
    sort(a+1,a+n+1,cmp);
    l=1;
    for(int r=1;r<=n;r++){
        while(a[r].l>a[l].r&&l<r)l++;
        cnt+=r-l;
    }
    cout<<cnt;
    return 0;
}
//note: