source_code: import java.io.*;
  import java.util.*;
  
  public class AA {
  	static class O implements Comparable<O> {
  		int problems;
  		int penalty;
  
  		public O(int p, int pp) {
  			problems = p;
  			penalty = pp;
  		}
  
  		public int compareTo(O arg0) {
  			if (problems == arg0.problems) {
  				return penalty - arg0.penalty;
  			}
  			return -(problems - arg0.problems);
  		}
  
  	}
  
  	public static void main(String[] args) throws IOException {
  		BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
  		String s = r.readLine();
  		String[] sp = s.split("[ ]+");
  		int n = new Integer(sp[0]), k = new Integer(sp[1]) - 1;
  		O[] arr = new O[n];
  		for (int i = 0; i < arr.length; i++) {
  			s = r.readLine();
  			sp = s.split("[ ]+");
  			arr[i] = new O(new Integer(sp[0]), new Integer(sp[1]));
  		}
  		Arrays.sort(arr);
  
  		int res = 1;
  
  		int i = k + 1;
  		while (i < arr.length && arr[i].problems == arr[k].problems
  				&& arr[i].penalty == arr[k].penalty) {
  			i++;
  			res++;
  		}
  
  		i = k - 1;
  		while (i >= 0 && arr[i].problems == arr[k].problems
  				&& arr[i].penalty == arr[k].penalty) {
  			i--;
  			res++;
  		}
  		System.out.println(res);
  
  	}
  }
  