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
n = int(input())
l = [list(map(int, input().split())) for i in range(n)]

a = sorted(l, key=lambda x:x[0])
b = sorted(l, key=lambda x:x[1])

if n % 2 == 1:
  print(b[n//2][1] - a[n//2][0] +1)
else:
  print((b[n//2][1]+b[n//2-1][1])-(a[n//2][0]+a[n//2-1][0])+1)
