// Problem: 166_A. Rank List
// Time complexity: nlogn
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.InputMismatchException;

public class R113_D2_A {

    public static void main(String[] args) throws NumberFormatException,
            IOException {
        // BufferedReader in = new BufferedReader(new
        // InputStreamReader(System.in));
        InputReader4 in = new InputReader4(System.in);
        int n = in.readInt();
        int k = in.readInt();
        p[] inp = new p[n];
        for (int i = 0; i < inp.length; i++) {
            inp[i] = new p(in.readInt(), in.readInt());
        }
        Arrays.sort(inp);
        for (int i = 0; i < inp.length;) {
            int j = i + 1;
            while (j < inp.length && inp[i].x == inp[j].x
                    && inp[i].y == inp[j].y) {
                j++;
            }
            int num = j - i;
            if (k <= num) {
                System.out.println(num);
                return;
            } else
                k -= num;
            i = j;
        }
    }

    static class p implements Comparable<p> {
        int x;
        int y;

        public p(int a, int b) {
            x = a;
            y = b;
        }

        public int compareTo(p o) {
            if (x > o.x)
                return -1;
            if (x < o.x)
                return 1;
            return y - o.y;
        }

    }

    static class InputReader4 {
        private InputStream stream;
        private byte[] buf = new byte[1000];
        private int curChar, numChars;

        public InputReader4(InputStream stream) {
            this.stream = stream;
        }

        private int read() {
            if (numChars == -1)
                throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int readInt() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public long readLong() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            long res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public String readString() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuffer res = new StringBuffer();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        private boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        private String readLine0() {
            StringBuffer buf = new StringBuffer();
            int c = read();
            while (c != '\n' && c != -1) {
                buf.appendCodePoint(c);
                c = read();
            }
            return buf.toString();
        }

        public String readLine() {
            String s = readLine0();
            while (s.trim().length() == 0)
                s = readLine0();
            return s;
        }

        public String readLine(boolean ignoreEmptyLines) {
            if (ignoreEmptyLines)
                return readLine();
            else
                return readLine0();
        }

        public char readCharacter() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            return (char) c;
        }

        public double readDouble() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, readInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') {
                c = read();
                double m = 1;
                while (!isSpaceChar(c)) {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, readInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }
    }

}