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

#include<cstdio>

using namespace std;

int main(){
    int n;

    while(scanf("%d",&n)==1){
        if((n>=0 && n<=7) || (n<0 && n%2==0)) 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 printf("Overflow!\n");
    }

    return 0;
}