Poj Solution 2591

http://poj.org/problem?id=2591

//* @author: 82638882@163.com
import java.util.*;
public class Main
{
 public static void main(String[] args)
 {
   TreeSet< Long> t=new TreeSet< Long>();
   Scanner in=new Scanner(System.in);
   int[] arr=new int[10000001];
   arr[0]=1;
   int k1=0,k2=0;
   for(int i=1;i< 10000001;i++)
    {
    int y1=arr[k1]*2+1;
    int y2=arr[k2]*3+1;
    arr[i]=Math.min(y1, y2);
    if(arr[i]==y1) k1++;
    if(arr[i]==y2) k2++;
     }
    while(in.hasNext())
    {
    int a=in.nextInt();
    System.out.println(arr[a-1]);
    }
  }
}