import java.util.Scanner;
public class 阶乘 {
public static void main(string[] args){
Scanner sc=new Scanner(System.in);
System.out.printIn("请输入一个整数");
int n=sc.nextInt();
System.out.printIn("结果为:"+f(n));
}
public static int f(int n){
int sum=1;
for(i=1;i<=n;++i){
sum*=i;
}
return sum;
}
}