import java.util.*;
public class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        while(in.hasNext()){
            int trees = Integer.parseInt(in.nextLine().trim());
            int[] peaches = new int[trees];
            for (int i = 0; i < trees; i++) {
                peaches[i] = Integer.parseInt(in.nextLine());
            }
            int[] revP = new int[trees];
            for(int i = 0; i < trees; i++){
            	revP[i] = peaches[i];
            }
            Arrays.sort(revP);
            int len1 = peaches.length;
            int len2 = revP.length;
            int[][] dp = new int[len1+1][len2+1];
			for(int i = 0; i < len1; i++){
				for(int j = 0; j < len2; j++){
					if(peaches[i] == revP[j]){
						dp[i+1][j+1] = dp[i][j] + 1;
					}else{
						dp[i+1][j+1] = Math.max(dp[i][j+1], dp[i+1][j]) > dp[i][j] ? Math.max(dp[i][j+1],dp[i+1][j]) : dp[i][j];
					}
				}
			}
			System.out.println(dp[len1][len2]);
        }
        in.close();
    }
}

AC