There are N integers X_1, X_2, \cdots, X_N, and we know that A_i \leq X_i \leq B_i. Find the number of different values that the median of X_1, X_2, \cdots, X_N can take.

Constraints

* 2 \leq N \leq 2 \times 10^5
* 1 \leq A_i \leq B_i \leq 10^9
* All values in input are integers.

Input

Input is given from Standard Input in the following format:


N
A_1 B_1
A_2 B_2
:
A_N B_N


Output

Print the answer.

Examples

Input

2
1 2
2 3


Output

3


Input

3
100 100
10 10000
1 1000000000


Output

9991
import java.util.*;
import java.io.*;

public class Main {

    private static final int M = 1_000_000_007;

    public Main(FastScanner in, PrintWriter out, int test) {
        int N = in.nextInt();
        long[] A = new long[N];
        long[] B = new long[N];

        for (int i = 0; i < N; i++) {
            A[i] = in.nextLong();
            B[i] = in.nextLong();
        }

        Arrays.sort(A);
        Arrays.sort(B);

        long ma = N % 2 == 1 ? A[N / 2] : (A[N / 2] + A[(N - 1) / 2]);
        long mb = N % 2 == 1 ? B[N / 2] : (B[N / 2] + B[(N - 1) / 2]);
        long res = mb - ma + 1;
        out.println(res);
    }

    private int count(int x) {
        int i = 1, sum = 0, res = 0;
        while (i + sum <= x) {
            sum += i;
            i++;
            res++;
        }
        return res;
    }

    private long pow(int x, int p) {
        long res = 1, a = x;
        while (p > 1) {
            if (p % 2 == 1)
                res = res * a % M;

            a = a * a % M;
            p /= 2;
        }
        res  = res * a % M;
        return res;
    }

    public static void main(String[] args) {
        PrintWriter out = new PrintWriter(System.out);
        // Scanner in = new Scanner(
                // new BufferedReader(new InputStreamReader(System.in)));
        FastScanner in = new FastScanner(System.in);

        // int T = in.nextInt();
        for (int t = 1; t <= 1; t++) {
            Main sol = new Main(in, out, t);
        }

        out.close();
    }
}


class FastScanner{
    private InputStream stream;
    private byte[] buf = new byte[1024];
    private int curChar;
    private int numChars;

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

    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++];
    }

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

    boolean isEndline(int c)
    {
        return c=='\n'||c=='\r'||c==-1;
    }

    int nextInt()
    {
        return Integer.parseInt(next());
    }

    long nextLong()
    {
        return Long.parseLong(next());
    }

    double nextDouble()
    {
        return Double.parseDouble(next());
    }

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

    String nextLine(){
        int c = read();
        while (isEndline(c))
            c = read();
        StringBuilder res = new StringBuilder();
        do{
            res.appendCodePoint(c);
            c = read();
        }while(!isEndline(c));
        return res.toString();
    }
}
