#include<iostream>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<set>
#include<map>
#include<functional>
#include<string>
#include<cstring>
#include<cstdlib>
#include<queue>
#include<utility>
#include<fstream>
#include<sstream>
#include<cmath>
#include<cstdio>
#include <ctime>
#include<cassert>
#include <pthread.h>


using namespace std;

#define MEM(a,b) memset(a,(b),sizeof(a))
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#define MIN(a,b) ((a) < (b) ? (a) : (b))

#define MP make_pair
#define pb push_back


#define maxn 100000
#define maxt 100
#define maxv 1000000000

typedef long long  LL;
typedef pair<int,int> pi;
typedef vector<int> vi;

typedef vector<pi> vpi;

int tree[maxn+2];

int read(int idx)
{
	int sum = 0;
	while (idx > 0) sum =(sum+tree[idx]), idx -= (idx & -idx);
	return sum;
}

void update(int idx ,int val)
{
	while (idx <= maxn) tree[idx]=(tree[idx]+val), idx += (idx & -idx);
}

int females[maxn+5];
int males[maxn+5];
int line[maxn+5];
pi all[maxn+5];

int main()
{
   int i,j,k,n,m,cs=0;

     scanf("%d",&n);
     assert(n>=1 && n<=maxn);
     map<int,int> F,M;

     for(i=0;i<n;i++)
     {
        int a,b;
        scanf("%d%d",&a,&b);
        assert(0<=a && a<=maxv && 0<=b && b<=maxv);
        females[i]=b;
        males[i]=a;
        all[i]=MP(a,b);
     }

     /* assigns each male and female an unique id between 1 and N */
     sort(males,males+n);
     sort(females,females+n);

     for(i=0;i<n;i++)
     {
        if(i)
        {
            assert(males[i]!=males[i-1]);
            assert(females[i]!=females[i-1]);
        }

        M[males[i]]=i+1;
        F[females[i]]=i+1;
     }


     for(i=0;i<n;i++)
     {
        int x=M[all[i].first],y=F[all[i].second];
        line[x]=y;
     }

     /* traverse from right to left for males, and update the position of it's corresponding female
         on a binary indexed tree */

     MEM(tree,0);
     LL ans=0;
     for(i=n;i>=1;i--)
     {
        int x=line[i];
        ans+=read(x);
        update(x,+1);
     }

     printf("%lld\n",ans);


	return 0;
}