#include <stdio.h>

int n, max;
int num[5005];
int dp[5005];

int main()
{
    scanf("%d", &n);
    for (int i = 0; i < n; i++)
    {
        scanf("%d", &num[i]);
        dp[i] = 1;
    }
    for (int i = 0; i < n; i++)
    {
        for (int j = i; j < n; j++)
        {
            if(num[j] < num[i])
                dp[i] = dp[i] > (dp[j] + 1) ? dp[i] : (dp[j] + 1);
        }
        if (dp[i] > max)
            max = dp[i];
    }
    printf("%d", max);
    return 0;
}

刚学动规的蒟蒻一枚