#include<iostream>
using namespace std;

int main()
{
	
	int num, total=1;
	
	cout << "Please enter a number : ";
	cin >> num;
	
	int temp = num;
	int score[num];

	for(int i=0; i<temp; i++)
	{
		score[i]=num;
		--num;
	}
	
	for(int i=0; i<temp; i++)
	{
		total*=score[i];
	}
	
	cout << "Answer : " << total;
	return 0;
}