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())
AB = [list(map(int, input().split())) for _ in range(n)]
A, B = zip(*AB)
A = sorted(A)
B = sorted(B)
if n%2:
    a_m = A[(n-1)//2]
    b_m = B[(n-1)//2]
else:
    a_m = A[n//2] + A[n//2 - 1]
    b_m = B[n//2] + B[n//2 - 1]
ans = b_m - a_m + 1
print(ans)