#include <bits/stdc++.h>
#include <atcoder/all>
using mint = atcoder::static_modint<998244353>;
//using mint = atcoder::static_modint<1000000007>;
using namespace std;
using namespace atcoder;
using ld = long double;
using ll = long long;
#define mp(a,b) make_pair(a,b)
#define rep(i,s,n) for(int i=s; i<n; i++)

int op(int x,int y){return max(x,y);}
int e(){return 0;}
int main(){
    int n;
    cin >> n;
    set<ll> S;
    vector<pair<ll,ll>> r(n);
    rep(i,0,n){
        cin >> r[i].first >> r[i].second;
        S.insert(r[i].first);
        S.insert(r[i].second);
    }
    map<ll,ll> f;
    int k=0;
    auto itr=S.begin();
    while(itr!=S.end()){
        f[*itr]=k;
        k++;
        itr++;
    }
    rep(i,0,n){
        r[i].first=f[r[i].first];
        r[i].second=f[r[i].second];
    }
    sort(r.begin(),r.end());
    segtree<int,op,e> seg(2*n);
    rep(i,0,n){
        int a=r[i].first,b=r[i].second;
        int score=seg.prod(0,a+1)+1;
        seg.set(b,score);
    }
    int ans=n-seg.all_prod();
    cout << ans;
}