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):
    cc=input("").split(" ")
    a+=[int(cc[0])]
    b+=[int(cc[1])]
s=0
a.sort()
b.sort()
if (n%2==0):
    s=(a[int(n/2)]+a[int(n/2)-1]-b[int(n/2)]-b[int(n/2)-1])
else:
    s=a[int((n-1)/2)]-b[int((n-1)/2)]
print(int(-s+1))
