#include<iostream>

using namespace std;

int giaithua(int n)
{
	if(n==0||n==1) return 1;
	else return n*giaithua(n-1);
}

int main(){
	long long a[100];
	int dem=0, n=1;
	do
	{
		cin>>n;
		a[dem] = giaithua(n);
		dem++;
	}while(n!=0);
	for(int i=0;i<dem-1;i++)
	{
		cout<<a[i]<<endl;
	}
	return 0;
}