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, *AB = map(int, open(0).read().split())
A = sorted(AB[::2])
B = sorted(AB[1::2])
if N % 2:
    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)
