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())

m=[]
M=[]
for i in range(N):
    a,b=map(int,input().split())
    m.append(a)
    M.append(b)
m.sort()
M.sort()

if N%2==1:
    print(M[N//2]-m[N//2]+1)
else:
    M1=(M[N//2-1]+M[N//2])/2
    m1=(m[N//2-1]+m[N//2])/2
    print(int((M1-m1)*2+1))