taylor min a

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

long readNumber();
long factorial(long b);

int main()
{
    long x;

    x = readNumber();
    factorial(x);
    printf("\nErg: %ld", factorial(x));

    return 0;
}

long readNumber()
{
    long i;
    printf("\nGeben Sie eine ganze Zahl ein: ");
    scanf("%ld", &i);
    return i;
}

long factorial(long b)
{
   long i, fact=1;

   if(b <= 0)
   {
    return 0;
   }

   for(i=1; i<=b ; i++)
   {
        fact = fact * i;
   }
   return fact;
}