#include <bits/stdc++.h>
using namespace std;
#include <atcoder/segtree>
using namespace atcoder;
using ll = long long;
using P = pair<ll,ll>;
#define fix(x) fixed << setprecision(x)
#define asc(x) x, vector<x>, greater<x>
#define rep(i, n) for(ll i = 0; i < n; ++i)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}
constexpr ll INFLL = (1LL << 62), MOD = 998244353;
constexpr int INF = (1 << 30);

int op(int a,int b){ return max(a,b); }
int e(){ return 0; }

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    vector<pair<int,int>> a(n);
    rep(i,n) cin >> a[i].first >> a[i].second;
    sort(all(a));
    segtree<int, op, e> dp(n+1);
    rep(i,n){
        int x = lower_bound(all(a), make_pair(a[i].second,0)) - a.begin();
        dp.set(x, max(dp.prod(0,i+1)+1, dp.get(i+1)));
    }
    cout << n-dp.get(n) << '\n';
    return 0;
}