#include <stdio.h>

main()
{
	int n;
	int factorial;

	printf("Enter a number: ");
	scanf("%d", &n); /* Read the number n */

	/* Calculate n! */
	for (factorial = 1; n > 0; n = n - 1)
		factorial = factorial * n;
	
	printf("%d", n);
	printf("! = ");
	printf("%d\n", factorial);
}