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.PrintWriter;
import java.math.*;
public class Main{
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		int[] a=new int[n];
		int[] b=new int[n];
		for(int i=0; i<n;i++){
			a[i]=sc.nextInt();
			b[i]=sc.nextInt();
		}
		Arrays.sort(a);
		Arrays.sort(b);
		if(n%2==0){
			System.out.println(b[n/2-1]+b[n/2]-(a[n/2-1]+a[n/2])+1);
		}else{
			System.out.println(b[n/2]-a[n/2]+1);
		}
	}
}
