Longest Increasing Subsequence - Recursion Method

//      Longest Increasing Sub-Sequence problem
//      Naive recursion method. Complexity O(2^n);
//      Wed Jul 25 01:09:10 IST 2012

import java.util.StringTokenizer;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class longestSubSequence{
    public static void main (String [] args)throws IOException{
        new longestSubSequence().run();
    }

    int max = -1;
    int index = 1;
    int [] array;
    private void run() throws IOException{
        array = new int [50];
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer (br.readLine());
        array[0] = -1;
        while (st.hasMoreTokens()){
                array[index++] = Integer.parseInt(st.nextToken());
        }
        index--;
        dfs (0,0);
        System.out.println(max);//      Prints the maximum length
    }

    private void dfs (int curr, int length){
        if (length > max )max = length;
        if (curr >= index)
            return ;
        for (int I=curr+1;I <= index; I++){
            if (array[I] >= array[curr]){
                dfs (I, length+1);
            }
        }
    }
}