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.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		int n = Integer.parseInt(sc.next());
		
		int []a = new int [n];
		int []b = new int [n];
		
		for(int i = 0 ; i < n ;i++) {
			a[i] = Integer.parseInt(sc.next());
			b[i] = Integer.parseInt(sc.next());
		}
		
		Arrays.sort(a);
		Arrays.sort(b);
		
		if(n % 2 == 1) {
			int low = a[(n-1)/2];
			int high = b[(n-1)/2];
			System.out.println(high - low +1);
		}
		else {
			int low = a[(n-2)/2] +a[n/2];
			int high = b[(n-2)/2] +b[n/2];
			System.out.println(high - low + 1);
		}
	}
}
