Q10323: Factorial! You Must be Kidding!!!

// Accepted !!

// strange problem — mathematically incorrect = =

#include <stdio.h>
#include <cstdlib>

int main()
{
    int n;
    while(scanf("%d",&n) != EOF)
    {
        if(n > 13)
            printf("Overflow!\n");
        else if(n >= 0)
        {
            switch(n)
            {
                case 13:
                     printf("6227020800\n");
                     break;
                case 12:
                     printf("479001600\n");
                     break;
                case 11:
                     printf("39916800\n");
                     break;
                case 10:
                     printf("3628800\n");
                     break;
                case 9:
                     printf("362880\n");
                     break;
                case 8:
                     printf("40320\n");
                     break;
                default:
                     printf("Underflow!\n");
            }
        }
        else
        {
            if(-n % 2 == 0)
                printf("Underflow!\n");
            else
                printf("Overflow!\n");
        }
    }

    system("PAUSE");
    return EXIT_SUCCESS;
}