#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<long long> VL;
typedef vector<VL> VVL;
typedef long long LL;
#define all(a) (a).begin(), (a).end()
#define Yes(n) cout << ((n) ? "Yes" : "No"  ) << endl
#define ALL(a)  (a).begin(),(a).end()
#define pb push_back

int A[200000];

int main() {
  int n;cin>>n;
  VVI R(n,VI(2));
  rep(i,n){
    cin>>R[i][0]>>R[i][1];
  }
  sort(all(R));
  rep(i,n){A[i]=-1;}
  A[0]=R[n-1][0];
  int siz=0;
  for(int i=n-2;i>=0;i--){
    if(A[siz]>=R[i][1]){siz++; A[siz]=R[i][1];}
    else if(A[0]<R[i][1]){}
    else{
      int l=0,r=siz,t;
      while(r-l>1){
        t=(r+l)/2;
        if(A[t]>=R[i][1]){l=t;}
        else{r=t;}
      }
      A[r]=max(A[r],R[i][0]);
    }
  }
  cout<<n-(siz+1)<<endl;
}