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())
a = []
b = []
for i in range(n):
  aa, bb = map(int, input().split())
  a.append(aa)
  b.append(bb)
a.sort()
b.sort()
ans = 0
if n%2 == 1:
  ans = b[n//2]-a[n//2]+1
else:
  ans = (b[n//2]-a[n//2])+(b[n//2-1]-a[n//2-1])+1
print (ans)