import java.util.Scanner;
public class jiecheng{
public static int jisuan(int n){
int r = 1;
for(int i=1;i<=n;i++)
r*=i;
return r;
}
public static void main(String args[]){
System.out.println("请输入需要求阶乘的数字(请输入一个整数):");
Scanner in = new Scanner(System.in);
int a = Integer.parseInt(in.nextLine());
System.out.println(digui(a))；
}
}
