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

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 & 1) cout << b[n / 2] - a[n / 2] + 1 << endl;
	else cout << (b[n / 2 - 1] + b[n / 2]) - (a[n / 2 - 1] + a[n / 2]) + 1 << endl;

	return 0;
}