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.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;

import java.util.*;

public class Main {
    long MOD = (long) 1e9 + 7;

    InputStream in;
    OutputStream out;

    public Main() {
        this(System.in, System.out);
    }

    public Main(InputStream in, OutputStream out) {
        this.in = in;
        this.out = out;
    }

    int n;
    int[] as, bs;

    void run() {
        Scanner sc = new Scanner(this.in);
        PrintWriter out = new PrintWriter(this.out);

        // write your code
        n = sc.nextInt();
        as = new int[n];
        bs = new int[n];

        for (int i = 0; i < n; i++) {
            as[i] = sc.nextInt();
            bs[i] = sc.nextInt();
        }
        Arrays.sort(as);
        Arrays.sort(bs);

        int min, max;
        if (n % 2 == 0) {
            min = (as[n / 2 - 1] + as[n / 2]);
            max = (bs[n / 2 - 1] + bs[n / 2]);
        } else {
            min = as[n / 2];
            max = bs[n / 2];
        }

        out.println(max - min + 1);
        out.flush();
    }

    void debug(Object... os) {
        System.err.println(Arrays.deepToString(os));
    }

    public static void main(String[] args) {
        new Main().run();
    }
}