10323

#include<stdio.h>
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>=14)
        {
            printf("Overflow!\n");
        }




    }
    return 0;
}