The 2018 ACM-ICPC China JiangSu Provincial Programming Contest J. Set

Let's consider some math problems.

JSZKC has a set A=A={1,2,...,N}. He defines a subset of A as 'Meo set' if there doesn't exist two integers in this subset with difference one. For example, When A={1,2,3},{1},{2},{3},{1,3} are 'Meo set'.

For each 'Meo set', we can calculate the product of all the integers in it. And then we square this product. At last, we can sum up all the square result of the 'Meo set'.

So please output the final result.

Input Format

The input file contains several test cases, each of them as described below.

• The first line of the input contains one integers N(1≤N≤100), giving the size of the set.

There are no more than 100test cases.

Output Format

One line per case, an integer indicates the answer.

样例输入

3

样例输出

23

题目来源

The 2018 ACM-ICPC China JiangSu Provincial Programming Contest

 

//要用java大数，规律为(n+1)!-1
import java.io.*;
import java.util.*;
import java.math.BigInteger;
public class a{
    public static void main(String args[]){
        Scanner cin=new Scanner (System.in);
        int  n;
        BigInteger a=BigInteger.valueOf(1);
        while(cin.hasNext()){
            n=cin.nextInt();
            BigInteger ans=BigInteger.valueOf(1);
            for(int i=1;i<=n+1;i++)
            {
                ans=ans.multiply(BigInteger.valueOf(i));
                //System.out.println(ans);
            }
            ans=ans.subtract(a);
            System.out.println(ans);
        }
    }
}