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())

s=[]
e=[]
for i in range(n):
  a,b=map(int,input().split())
  s.append(a)
  e.append(b)

s=sorted(s)
e=sorted(e,reverse=True)

x=n//2
if n%2==1:
  ans=(e[x]-s[x]+1)

else:
  ts=(s[x]+s[x-1])/2
  te=(e[x]+e[x-1])/2
  ans=(te-ts)//0.5+1

print(int(ans))