#include<bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define mp make_pair
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
template<typename T> bool chkmin(T&x,T y){return x>y?x=y,1:0;}
template<typename T> bool chkmax(T&x,T y){return x<y?x=y,1:0;}
int readint(){
int x=0,f=1; char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
return x*f;
}
int n,x[300005],y[300005];
map<int,int> cx,cy;
int main(){
n=readint();
for(int i=1;i<=n;i++)x[i]=readint(),y[i]=readint(),cx[x[i]]++,cy[y[i]]++;
ll ans=0;
for(int i=1;i<=n;i++)ans+=(cx[x[i]]-1)*1LL*(cy[y[i]]-1);
printf("%lld\n",ans);
return 0;
}
