#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; (i) < int(n); ++ (i))
using namespace std;

int main() {
    // input
    int n; cin >> n;
    vector<int> a(n);
    REP (i, n) cin >> a[i];

    // solve
    REP (i, n) a[i] -= 1;
    multiset<int> dp;
    int shift = 0;
    for (int a_i : a) {
        auto it = dp.lower_bound(a_i);
        if (it != dp.end()) {
            dp.erase(it);
            ++ shift;
        }
        dp.insert(a_i);
    }

    // output
    cout << shift << endl;
    return 0;
}