Hat's Fibonacci

import java.util.*;
import java.math.*;
public class Main
{
    public static void main(String []args)
    {
        Scanner cin=new Scanner(System.in);
        int i,n;
        while(cin.hasNext())
        {    
            n=cin.nextInt();
            BigInteger s1 = BigInteger.valueOf(1);
            BigInteger s2 = BigInteger.valueOf(1);
            BigInteger s3 = BigInteger.valueOf(1);
            BigInteger s4 = BigInteger.valueOf(1);
            BigInteger s5 = BigInteger.valueOf(1);
            for(i=5;i<=n;i++)
            {
                s5 = s4.add(s3.add(s2.add(s1)));
                s1=s2;
                s2=s3;
                s3=s4;
                s4=s5;
            }
            System.out.println(s5);    
        }
    }
}

果断的一个大数问题，担心自己用C或者C++过不了，果断用了Java来做，用Java做这种题，确实简单，也记下自己的脚印吧！