Poj Solution 2084

http://poj.org/problem?id=2084

import java.io.*; 
import java.util.*; 
import java.math.BigInteger;
public  class Main { 
 public static void main(String[]args){ 
  Scanner sin=new Scanner(new BufferedInputStream(System.in)); 
   int n;
   int i = 0; 
   BigInteger big[] = new BigInteger[101];
   for(i = 0 ; i < 101 ; i++)
    big[i] = new BigInteger("0");
    big[0] = big[1].add(new BigInteger("1"));
    big[1] = big[1].add(new BigInteger("1"));
  for(i=2; i < 101 ; i++){
   for(int j = 0 ; j < i ; j++){
    big[i] = big[i].add(big[j].multiply(big[i-1-j]));  
   }
}

while(true){ 
 n=sin.nextInt(); 
 if(n == -1)break;
   System.out.println(big[n].toString()); 

}

}
}