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 _ in range(N):
    A,B=map(int,input().split())
    a.append(A)
    b.append(B)
a=sorted(a)
b=sorted(b)
if N%2==1:
    print(b[N//2]-a[N//2]+1)
else:
    print((b[N//2-1]+b[N//2])-(a[N//2-1]+a[N//2])+1)