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, B = sorted(A), sorted(B)
m1 = A[N//2] + A[(N-1)//2]
m2 = B[N//2] + B[(N-1)//2]
print((m2 - m1) // (N % 2 + 1) + 1)