source_code: 
  import java.awt.Point;
  import java.util.Arrays;
  import java.util.Comparator;
  import java.util.Scanner;
  
  public class A {
      public static void main(String[] args) {
          Scanner in = new Scanner(System.in);
          int n = in.nextInt();
          int k = in.nextInt() - 1;
          Point[] A = new Point[n];
          for (int i = 0; i < n; i++)
              A[i] = new Point(in.nextInt(), in.nextInt());
          Arrays.sort(A, new Comparator<Point>() {
              public int compare(Point o1, Point o2) {
                  if (o1.x != o2.x)
                      return o2.x - o1.x;
                  if (o1.y != o2.y)
                      return o1.y - o2.y;
                  return 0;
              }
          });
          int i = k;
          int j = k;
          while (i >= 0 && A[i].x == A[k].x && A[i].y == A[k].y)
              i--;
          while (j < n && A[j].x == A[k].x && A[j].y == A[k].y)
              j++;
          System.out.println(j - i - 1);
      }
  }
  