81
9 4
6 8
6 4
4 6
4 8
9 10
0 2
5 4
8 9
7 7
10 5
4 4
7 8
3 7
2 1
5 5
2 7
8 6
2 8
10 7
5 8
0 10
10 0
4 9
4 2
10 3
6 6
3 8
5 3
8 8
10 9
1 1
0 9
8 1
1 8
0 7
10 4
3 6
7 6
1 9
8 3
8 10
4 5
3 4
7 5
2 0
0 6
2 4
7 4
6 3
1 6
10 8
1 5
6 5
0 0
9 0
7 3
3 2
2 6
4 0
8 7
10 10
3 0
0 5
3 9
5 1
6 0
1 4
0 1
1 2
6 2
9 7
6 10
1 3
1 7
2 5
5 10
10 2
5 6
6 7
2 3
 1
0 0
 3
5 1
4 1
2 6
 54
0 8
3 2
9 3
7 2
8 2
2 8
10 10
7 6
1 1
9 7
4 0
6 10
10 1
10 8
5 1
0 4
7 10
3 6
0 5
4 3
3 0
5 10
6 9
5 4
6 6
8 5
0 7
5 8
1 2
2 2
9 4
2 4
0 10
5 9
10 9
7 9
9 9
2 5
4 10
8 9
7 7
5 2
6 5
4 1
10 6
6 3
9 6
0 9
7 3
7 5
8 4
1 3
0 3
2 10
 49
2 9
7 0
8 0
10 3
2 10
6 10
6 2
9 7
1 9
4 6
5 4
1 0
9 4
6 9
5 6
7 9
10 10
8 2
3 10
0 8
4 4
5 7
0 0
9 1
0 7
2 0
1 7
10 0
3 5
8 5
6 4
0 4
2 7
4 1
10 2
2 4
8 4
0 9
3 4
4 9
7 7
10 9
2 3
7 2
5 8
4 7
10 8
7 6
1 8
 72
8 2
2 4
3 5
9 10
7 6
1 5
0 0
3 3
1 6
7 10
8 8
7 9
6 0
3 6
9 3
8 1
3 4
3 7
0 7
10 8
2 6
6 8
0 6
5 6
6 6
6 5
6 4
0 2
9 9
4 8
7 2
8 0
9 4
0 10
4 5
9 8
10 3
8 7
8 5
7 7
6 7
5 7
5 4
8 4
3 2
7 3
9 0
0 8
0 5
3 9
2 10
7 1
4 3
1 10
3 0
5 9
10 1
6 1
4 10
1 0
2 1
2 0
3 8
10 7
7 4
0 9
1 1
1 8
8 3
5 2
6 3
4 2
 71
5 3
1 10
10 3
5 2
3 5
10 9
10 2
1 5
9 5
8 9
2 3
2 6
8 4
6 3
0 2
9 4
2 0
7 7
10 0
4 0
1 4
1 6
4 5
6 1
8 2
0 0
0 1
3 7
3 10
4 8
4 6
3 8
1 0
9 10
9 9
6 5
7 1
10 1
6 6
3 4
4 3
4 2
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9 6
7 3
6 8
5 5
4 9
0 7
0 9
8 10
2 7
1 7
7 2
5 8
1 2
3 6
10 8
0 8
3 1
1 3
9 3
7 6
6 7
4 4
0 3
2 2
5 10
2 9
0 5
7 0
 3
1 6
10 8
4 3
 1
100000 100000
 87
5 10
5 0
9 2
2 4
6 6
4 4
3 4
0 3
10 6
1 0
7 1
2 5
6 10
5 3
1 6
8 7
5 6
5 9
9 8
2 6
6 9
6 4
3 2
10 10
0 4
8 9
8 8
4 8
10 2
10 0
3 8
8 2
3 1
9 5
9 1
5 4
4 6
10 7
2 0
10 9
9 0
9 9
6 2
3 9
10 8
7 0
7 3
6 0
5 2
6 5
4 7
1 3
9 7
1 5
4 1
7 10
0 2
0 8
9 10
0 5
4 10
7 4
1 8
2 7
10 3
9 3
10 5
6 1
8 3
10 1
8 0
5 1
3 10
10 4
2 10
4 5
5 7
7 9
1 7
8 6
1 1
7 2
7 5
5 5
1 4
6 8
6 3

85
 0
 0
 14
 11
 51
 40
 0
 0
 101

#include <iostream>
#include <cstdio>
#include <unordered_set>
#include <vector>
#include <algorithm>

using namespace std;

vector <int > a[100001];

namespace std{
template <>
class hash <pair <int, int> >{
    public:
    size_t operator ()(const pair <int, int> & a) const{
        return (a.first + a.second * 100007) % 12345678;
    }
};
};

main () {
    ios_base :: sync_with_stdio(false);
    cin.tie(NULL);
    int n;
    cin >> n;
    unordered_set <pair <int, int >> s;
    pair<int, int> b[n];
    for (int i = 0; i < n; ++i) {
        cin >> b[i].first >> b[i].second;
        s.insert({b[i].first, b[i].second});
        a[b[i].first].push_back (b[i].second);
    }
    sort (b, b + n);
    int ans = 0;
    for (int i = 0; i < n; ++i) {
        int xx = b[i].first;
        int p = lower_bound(a[xx].begin (), a[xx].end (), b[i].second) - a[xx].begin ();
        for (int j1 = 0; j1 < p; ++j1) {
            if (a[xx][j1] == b[i].second) continue;
            int y1 = b[i].second;
            int y2 = a[xx][j1];
            int k = abs(y1 - y2);
            if (s.count({xx + k, y1}) && s.count({xx + k, y2})) ++ans;
        }
    }
    cout << ans;
}
