import java.util.Arrays;
import java.util.HashMap;

public class Main {
	static final int M=11000;
	static class P implements Comparable<P>{
		static final HashMap<Integer,P> ps=new HashMap<Integer,P>();
		int x,y,c=0;P p;
		P(int i,int j){
			x=i;y=j;
			ps.put(x*M+y,this);
			b(this,ps.get((x+1)*M+y));
			b(this,ps.get((x-1)*M+y));
			b(this,ps.get(x*M+y+1));
			b(this,ps.get(x*M+y-1));
		}
		P r(int t){
			if(p==null)
				return this;
			if(t>2000){//防止 stack over follow
				while(p.p!=null)
					p=p.p;
				return p;
			}
			while(p.r(t+1)!=p)
				p=p.r(t+1);
			return p;
		}
		static void b(P a,P b){
			if(a==null || b==null)
				return ;
			if(a.x*M+a.y>b.x*M+b.y)
				a.r(0).p=b.r(0);
			else
				b.r(0).p=a.r(0);			
		}
		public boolean equals(Object obj) {return ((P)obj).x==x &&((P)obj).y==y;}
		public int compareTo(P o) {return c>o.c?-1:(c==o.c?0:1);}
	}
	final static int ni() {
		int v = 0;
		char t = 0;
		boolean neg = false;
		try {
			while (!Character.isDigit(t = (char) System.in.read()) && t != '-')
				;
			if (t == '-') {
				neg = true;
				t = '0';
			}
			do {
				v *= 10;
				v += t - '0';
			} while (Character.isDigit(t = (char) System.in.read()));
		} catch (Exception e) {
		}
		return neg ? -v : v;
	}

	public static void main(String[] args) {
		int n=ni(),k=ni();
		for(int i=0;i<n;i++)
			new P(ni(),ni());
		P ps[]=new P[P.ps.values().size()];
		ps=P.ps.values().toArray(ps);
		for(P p:ps)
			p.r(0).c++;
		Arrays.sort(ps);
		int r=0;
		for(int i=0;i<k;i++)r+=ps[i].c;
		System.out.println(r);
	}

}