#include <stdio.h>
#include <stdlib.h>
#include <time.h>

unsigned long fakt(int a) {

	unsigned long f = 1;
	
	for (int i = 1 ; i <= a; i++)
		f *= i; 

	return f;
}

int main() {

	int num;
	printf("bir sayi giriniz: "); 
	scanf("%d",&num);
	printf("%lu\n",fakt(num));
	
}