1134
import java.io.*;
import java.math.*;
import java.util.*;
public class Main{
public static void main(String []args){
Scanner cin = new Scanner(System.in);
Integer N = 101,i;
BigInteger []cat = new BigInteger[N];
cat[0] = cat[1] = BigInteger.valueOf(1);
for(i = 2; i < N; ++i){
cat[i] = cat[i-1].multiply(BigInteger.valueOf(i*4-2)).divide(BigInteger.valueOf(i+1));
}
while(cin.hasNext()){
i = cin.nextInt();
if(i == -1)
break;
System.out.println(cat[i]);
}
}
}
This is a small but ancient game. You are supposed