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,*t=map(int,open(0).read().split())
A=sorted(t[0::2])
B=sorted(t[1::2])
if n%2==0:
    kl=n//2-1
    kr=n//2
else:
    kl=n//2
    kr=n//2
lm,lM=A[kl],A[kr]
rm,rM=B[kl],B[kr]
L,R=0,0
if n%2==0:
    L=lm+lM
    R=rm+rM
    a=R-L+1
else:
    a=rm-lm+1
print(a)