B3637
40分

#include <bits/stdc++.h>
using namespace std;
int n, a[5005], dp[5005];
int main(){
	cin >> n;
	dp[n] = 1;
	for (int i = 1; i <= n; i++) cin >> a[i];
	for (int i = n; i >= 1; i--){
		for (int j = i + 1; j <= n; j++){
			if(a[j] > a[i]) dp[i] = max(dp[i], dp[j] + 1); 
		}
	}
	int max_len = 1;
    for (int i = 1; i <= n; i++) max_len = max(max_len, dp[i]);
    cout << max_len;
	return 0;
}