#include<bits/stdc++.h>
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;
  }
  else{
  	cout<<b[n/2]+b[n/2-1]-a[n/2]-a[n/2-1]+1;
  }
}