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