UVA 10323 - Factorial! You Must be Kidding!!!

#include
int main()
{
long long n;
while(scanf("%lld",&n)==1)
{
if(n<0&&n%2==0)
printf("Underflow!\n");
else if(n<0&&n%2!=0)
printf("Overflow!\n");
else if(n==0||n<=7)
printf("Underflow!\n");
else if(n==8)
printf("40320\n");
else if(n==9)
printf("362880\n");
else if(n==10)
printf("3628800\n");
else if(n==11)
printf("39916800\n");
else if(n==12)
printf("479001600\n");
else if(n==13)
printf("6227020800\n");
else if(n>13)
printf("Overflow!\n");
}
return 0;
}