p0.cpp

好东西,绝对是好东西,我向大家推荐

#include <iostream.h>
long long fac(long long n)
{
	if(n==1||n==0)
	{
		return(1);
	}
	else return(n*fac(n-1));	
}
int main()
{
	long long n,s;
	while(cin>>n)
	{
		s=1;
		s=fac(n);
	
	cout<<s<<endl;
	}
}