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.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = Integer.parseInt(scan.next());
        Integer[] a = new Integer[n];
        Integer[] b = new Integer[n];
        for (int i = 0; i < n; i++) {
            a[i] = Integer.parseInt(scan.next());
            b[i] = Integer.parseInt(scan.next());
        }
        scan.close();

        Arrays.sort(a);
        Arrays.sort(b);

        if (n % 2 == 1) {
            System.out.println(b[(n - 1) / 2] - a[(n - 1) / 2] + 1);
        } else {
            int alow = a[n / 2 - 1];
            int ahigh = a[n / 2];
            int blow = b[n / 2 - 1];
            int bhigh = b[n / 2];
            System.out.println(blow + bhigh - alow - ahigh + 1);
        }

    }

}
