Hat's Fibonacci

 1 //package com.company;
 2 import java.math.BigInteger;
 3 import java.util.Scanner;
 4 public class Main{
 5     public static void main(String[] args){
 6         Scanner in=new Scanner(System.in);
 7         BigInteger f[]=new BigInteger[10000];
 8         f[1]=f[2]=f[3]=f[4]=BigInteger.valueOf(1);
 9         for (int i = 5; i < 10000; i++) {
10             f[i] = f[i-1].add(f[i-2]).add(f[i-3]).add(f[i-4]);
11         }
12         while(in.hasNext()){
13             int n=in.nextInt();
14             System.out.println(f[n]);
15         }
16     }
17 }