N!

Given an integer N(0 ≤ N ≤ 10000), your task is to calculate N!

 

Input

One N in one line, process to the end of file.

 

Output

For each N, output N! in one line.

 

Sample Input

1
2
3

 

Sample Output

1
2
6

此题主要是解决在a.multiply(i)再mulitply()中不能够用整形,必须是大整形所以可以改为multiply(new BigInteger(""+i)  );

import java.util.*;
import java.io.*;
import java.math.*;
public class Main
{
  static BigInteger[] ans;//注意定义大数的数组的放法再BigInteger后边加上数组的符号[].
	public static void main(String[] args)
	{
		Scanner cin=new Scanner(System.in);
		//BigInteger i;
		int i,n;
		ans=new BigInteger[10010];
		ans[0]=BigInteger.valueOf(1);
		ans[1]=BigInteger.valueOf(1);
		ans[2]=BigInteger.valueOf(2);
		for(i=3;i<=10001;i++)
		{
			ans[i]=ans[i-1].multiply(new BigInteger(""+i)   );
		}
		while(cin.hasNext())
		{
			n=cin.nextInt();
			System.out.println(ans[n]);
		}
	}
}