Java函数调用求N的阶乘

import java.util.Scanner;
public class studying { 
    private static int fact(int num){
        int fact=1;
        for(int i=1;i<=num;i++)
            fact*=i;
        return fact;
    }
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        int num=input.nextInt();
        System.out.println(fact(num));
    }
}