//KZNS
#include <fstream>
using namespace std;
ifstream fin ("lunch.in");
ofstream fout ("lunch.out");
int ls[100003] = {0};
int tl = 0;
int N;
int main() {
	fin >> N;
	int a;
	int l, r;
	ls[0] = 0x7fffffff;
	for (int i = 0; i < N; i++) {
		fin >> a;
		if (!a) continue;
		if (a < ls[tl]) {
			ls[++tl] = a;
			continue;
		}
		l = 0; r = tl;
		while (r-l>1) {
			if (ls[l+r>>1] > a)
				l = l+r>>1;
			else
				r = l+r>>1;
		}
		ls[r] = a;
	}
	fout << tl;
	return 0;
}
//UBWH