C language programming> Twenty-third week① In the following given program, the function of the function fun is: find n! (n<20), and the value of the factorial sought is returned as the function value. For example, if n=5, 120 should be output.

Example: In the following given program, the function of the function fun is: find n! (n<20), and the value of the factorial sought is returned as the function value. For example, if n=5, 120 should be output.

请修改程序中的错误，得出正确的结果。
注意：不要改动main函数，不能增行或删行，也不能更改程序的结构。

代码如下：

#include<conio.h>
#include<stdio.h>
long fun(int n)
{
    
    
	if(n>1)
		return(n*fun(n-1));
	return  1;
}
main()
{
    
    
	int n=5;
	printf("%d!=%ld\n",n,fun(n));
}

The output running window is as follows:

越努力越幸运！
加油，奥力给！！！