import java.util.Scanner;
/*
* 要求:遞歸算法求n!
*
* */
public class jianchengdigui {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int sum = f(n);
System.out.println(sum);
}
private static int f(int n) {
if(n==1){
return 1;
}
return n*f(n-1);
}
}
效果圖