#include<iostream>
using namespace std;

int main(){
    int n;
    cin >> n;
    
    if(n <= 0) {
        cout << "Invalid input";
    }
    else if(n > 12) {
        cout << "Overflow occurred";
    }
    else {
        long long fact = 1;
        for(int i = 1; 1 <= n; i++)
        fact *= i;
        
        
    }
    return 0;
}