81
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7 7
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8 7
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9 7
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 54
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 49
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 72
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100000 100000
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6 8
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85
 0
 0
 14
 11
 51
 40
 0
 0
 101

import java.io.*;
import java.util.*;

public class D implements Runnable {
	public static void main (String[] args) {new Thread(null, new D(), "_cf", 1 << 28).start();}

	int res = 0, n;
	HashSet<Long> set = new HashSet<>();
	Point[] a;
	
	public void run() {
		FastScanner fs = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);
		System.err.println("");

		n = fs.nextInt();
		a = new Point[n];
		for(int i = 0; i < n; i++) {
			a[i] = new Point(fs.nextInt(), fs.nextInt());
			set.add(getMask(a[i].x, a[i].y));
		}
		Arrays.sort(a);
		
		solve(0, n-1);
		out.println(res);
		
		out.close();
	}
	
	double eps = 0;
	void solve(int L, int R) {
		if(R < L || L < 0 || R >= n) return;
		if(a[L].x == a[R].x) return;
		
		double X = (a[L].x+a[R].x)/2.0;
//		System.out.println("X " + X);
		
		boolean half = false;
		int nR = L;
		int nL = R;
		
		for(int i = L; i <= R; i++) {
			if(Math.abs(a[i].x-X) < 1e-6) {
				if(!half) nR = i-1;
				nL = i+1;
				half = true;
				continue;
			}
			double dist = Math.abs(X-a[i].x);
//			System.out.println("Working on " + a[i]);
			
			int x = a[i].x, y = a[i].y;
			int nx = (int)(x+2*dist+eps), ny = y;
			int nx2 = x, ny2 = (int)(y-2*dist-eps);
			int nx3 = nx, ny3 = ny2;
			
//			System.out.println("- " + new Point(nx, ny).toString() + " " + new Point(nx2, ny2).toString() + " " + new Point(nx3, ny3).toString());
			
			boolean match = nx <= a[R].x;
			match &= set.contains(getMask(nx, ny));
			match &= set.contains(getMask(nx2, ny2));
			match &= set.contains(getMask(nx3, ny3));
			
			if(match && !half) {
//				System.out.println(" fnd1");
				res++;
			}
			
			nx = (int)(x+dist+eps); ny = y;
			nx2 = x; ny2 = (int)(y-dist-eps);
			nx3 = nx; ny3 = ny2;
			if(half) {
				nx = (int)(x-dist-eps); ny = y;
				nx2 = x; ny2 = (int)(y-dist-eps);
				nx3 = nx; ny3 = ny2;
			}
			
//			System.out.println("> " + new Point(nx, ny).toString() + " " + new Point(nx2, ny2).toString() + " " + new Point(nx3, ny3).toString());
			
			match = true;
			match &= set.contains(getMask(nx, ny));
			match &= set.contains(getMask(nx2, ny2));
			match &= set.contains(getMask(nx3, ny3));
			
			if(match) {
//				System.out.println(" fnd2");
				res++;
			}
		}
		
		solve(L, nR);
		solve(nL, R);
	}
	
	long getMask(int a, int b) {
		long res = b;
		res |= (long)a << 32L;
		return res;
	}

	class Point implements Comparable<Point> {
		int x, y;
		Point(int a, int b) {
			x = a; y = b;
		}
		public int compareTo(Point p) {
			int comp = Integer.compare(x, p.x);
			if(comp == 0) comp = Integer.compare(p.y, y);
			return comp;
		}
		public String toString() {
			return String.format("(%d, %d)", x, y);
		}
	}
	
	class FastScanner {
		public int BS = 1<<16;
		public char NC = (char)0;
		byte[] buf = new byte[BS];
		int bId = 0, size = 0;
		char c = NC;
		double num = 1;
		BufferedInputStream in;

		public FastScanner() {
			in = new BufferedInputStream(System.in, BS);
		}

		public FastScanner(String s) {
			try {
				in = new BufferedInputStream(new FileInputStream(new File(s)), BS);
			}
			catch (Exception e) {
				in = new BufferedInputStream(System.in, BS);
			}
		}

		public char nextChar(){
			while(bId==size) {
				try {
					size = in.read(buf);
				}catch(Exception e) {
					return NC;
				}                
				if(size==-1)return NC;
				bId=0;
			}
			return (char)buf[bId++];
		}

		public int nextInt() {
			return (int)nextLong();
		}

		public long nextLong() {
			num=1;
			boolean neg = false;
			if(c==NC)c=nextChar();
			for(;(c<'0' || c>'9'); c = nextChar()) {
				if(c=='-')neg=true;
			}
			long res = 0;
			for(; c>='0' && c <='9'; c=nextChar()) {
				res = (res<<3)+(res<<1)+c-'0';
				num*=10;
			}
			return neg?-res:res;
		}

		public double nextDouble() {
			double cur = nextLong();
			return c!='.' ? cur:cur+nextLong()/num;
		}

		public String next() {
			StringBuilder res = new StringBuilder();
			while(c<=32)c=nextChar();
			while(c>32) {
				res.append(c);
				c=nextChar();
			}
			return res.toString();
		}

		public String nextLine() {
			StringBuilder res = new StringBuilder();
			while(c<=32)c=nextChar();
			while(c!='\n') {
				res.append(c);
				c=nextChar();
			}
			return res.toString();
		}

		public boolean hasNext() {
			if(c>32)return true;
			while(true) {
				c=nextChar();
				if(c==NC)return false;
				else if(c>32)return true;
			}
		}
		
		public int[] nextIntArray(int n) {
			int[] res = new int[n];
			for(int i = 0; i < n; i++) res[i] = nextInt();
			return res;
		}
		
	}

}