SuperCentral_Point.cpp

//********nikhiljugale007**********//

#include<bits/stdc++.h>
#include<iostream>
#include<vector>
#include<cstring>
#include<algorithm>
#include<set>
#include<iterator>

using namespace std;

#define fast        ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define ll          long long 
#define v           vector<ll int>
#define it          iterator it
#define pb          push_back
#define f(a,b)      for(long long int i=a;i<b;i++)
#define fv(v)       for(auto i=v.begin() ; i!=v.end();i++)
#define min         min_element
#define max         max_element
#define hell        1000000007


int main()
{
    int n, t(0);
    cin >> n;
    int x[n], y[n];

    for (int i = 0; i < n; i++)
        cin >> x[i] >> y[i];

    for (int i = 0; i < n; i++)
    {
        bool r = false, l= false, u = false, d = false;
        for (int j = 0; j < n; j++)
        {
            if (x[j] > x[i] and y[j] == y[i]) r = true;
            if (x[j] < x[i] and y[j] == y[i]) l = true;
            if (x[j] == x[i] and y[j] > y[i]) u = true;
            if (x[j] == x[i] and y[j] < y[i]) d = true;
        }
        if (r and l and u and d) t++;
    }

    cout << t << endl;
    return 0;
}