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 sc = new Scanner(System.in);

		int n = sc.nextInt();

		long[] a = new long[n], b = new long[n];
		for (int i = 0; i < n; i++) {
			a[i] = sc.nextLong();
			b[i] = sc.nextLong();
		}
		Arrays.sort(a);
		Arrays.sort(b);

		int mid = n / 2;
		if (n % 2 == 0) { // .5も含む
//			double min = (a[mid - 1] + a[mid]) / 2;
//			double max = (b[mid - 1] + b[mid]) / 2;
//			System.out.println((int) (max - min) * 2 + 1); // (max-min+1)*2-1
			
			// 整数で扱っても結果は変わらない．
			long min = (a[mid - 1] + a[mid]);
			long max = (b[mid - 1] + b[mid]);
			System.out.println(max - min + 1);
		} else {
			// 整数値のみ
			System.out.println(b[mid] - a[mid] + 1);
		}
	}
}
