source_code: 
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.PrintStream;
  import java.util.Arrays;
  import java.util.Comparator;
  import java.util.StringTokenizer;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  public class ProblemA {
  
      private final BufferedReader in;
      private final PrintStream out;
      private StringTokenizer tok = new StringTokenizer("");
      private String nextLine = null;
  
      public static void main(String[] args) throws Exception {
          new ProblemA();
      }
  
      private ProblemA() throws Exception {
          in = new BufferedReader(new InputStreamReader(System.in));
          out = System.out;
          start();
          end();
      }
  
      private int nextInt() {
          return Integer.parseInt(nextWord());
      }
  
      private String nextWord() {
          if (tok.hasMoreTokens()) {
              return tok.nextToken();
          } else {
              while (!tok.hasMoreTokens()) {
                  try {
                      nextLine = in.readLine();
                      if (nextLine == null) {
                          return null;
                      } else {
                          tok = new StringTokenizer(nextLine);
                      }
                  } catch (IOException ex) {
                      Logger.getLogger(ProblemA.class.getName()).log(Level.SEVERE, null, ex);
                  }
              }
              return tok.nextToken();
          }
      }
  
      private void start() {
          int n = nextInt();
          int k = nextInt();
          T[] ts = new T[n];
          for (int i = 0; i < n; i++) {
              ts[i] = new T(nextInt(), nextInt());
          }
          Arrays.sort(ts, new Comparator<T>() {
  
              @Override
              public int compare(T o1, T o2) {
                  if (o1.p > o2.p) {
                      return -1;
                  }
                  if (o1.p < o2.p) {
                      return 1;
                  }
                  if (o1.t < o2.t) {
                      return -1;
                  }
                  if (o1.t > o2.t) {
                      return 1;
                  }
                  return 0;
              }
          });
          int t = ts[k - 1].t;
          int p = ts[k - 1].p;
          int res = 0;
          for (int i = 0; i < n; i++) {
              if (ts[i].p == p && ts[i].t == t) {
                  res++;
              }
          }
          out.println(res);
      }
  
      class T {
  
          int p;
          int t;
  
          public T(int p, int t) {
              this.p = p;
              this.t = t;
          }
      }
  
      private void end() {
          out.close();
      }
  }
  