#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int n;
    cin >> n;

    vector<int> a(n), b(n);
    for (int i = 0; i < n; i++)cin >> a[i] >> b[i];
    sort(a.begin(), a.end()), sort(b.begin(), b.end());

    if (n % 2 == 1)cout << b[n / 2] - a[n / 2] + 1 << endl;
    else cout << (b[n / 2] + b[n / 2 - 1]) - (a[n / 2] + a[n / 2 - 1]) + 1 << endl;
    return 0;
}