hdu 1042

用java水过了。。937ms.

import java.io.*;
import java.util.*;
import java.math.*;

public class abc {
           public static void main(String[] args)
           {
        	 int t,i;
        	 Scanner cin=new Scanner(System.in);
        	 BigInteger sum;
        	 
        	 while(cin.hasNextInt())
        	 {
        	  sum=BigInteger.valueOf(1);
        	 t=cin.nextInt();
        	 for(i=1;i<=t;i++)
        	 sum=sum.multiply(BigInteger.valueOf(i));
             System.out.println(sum);
        	 }
           }
}