#include <stdio.h>

int factorial(int n)
{
	if (n == 1)
	{
		return 1;
	}
	else
	{
		return n*factorial(n-1);
	}
}


int main()
{
	int number;
	int s;

	printf("enter a number:\n");
	scanf("%d", &number);

	s = factorial(number);
	printf("the result is %d\n", s);
}