#include<bits/stdc++.h>
using namespace std;
#define ll long long
ll fact[15];
void factorial(){
    fact[0]=1;
    for(int i=1;i<=13;i++){
        fact[i]=fact[i-1]*i;
    }
}
int main()
{
    factorial();
    int n;
    while(cin>>n){
        if(n<8)
            cout<<"Underflow!"<<endl;
        else if(n>13)
            cout<<"Overflow!"<<endl;
        else
            cout<<fact[n]<<endl;
    }
}