#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
  int n;
  cin >> n;
  vector<int> ai(n), bi(n);
  for(int i=0; i<n; ++i) cin >> ai[i] >> bi[i];
  sort(ai.begin(),ai.end());
  sort(bi.begin(),bi.end());
  if(n%2){
    cout << bi[n/2]-ai[n/2]+1 << endl;
    return 0;
  }
  int a1 = ai[n/2-1], a2 = ai[n/2];
  int b1 = bi[n/2-1], b2 = bi[n/2];
  cout << (b1-a1) + (b2-a2) +1 << endl;
}