#include <fstream>
#include <vector>
using namespace std;
ifstream cin("scmax.in");
ofstream cout("scmax.out");
int n;
vector <int> v, dp;
int main()
{
    cin >> n;
    v.resize(n+1);
    dp.resize(n+1);
    dp[1] = 1;
    for(int i=2; i<=n; i++)
        cin >> v[i];
    for(int i=1; i<=n; i++)
        for(int j=1; j<i; j++)
            if(v[j] < v[i])
                dp[i] = max(dp[i], dp[j] + 1);
    cout << dp[n];
    return 0;
}