// A PROGRAM FOR PASSENGER FARE, IF AGE IS BELOW 12 THERE IS A 10% DISCOUNT ELSE 5%
#include <iostream>
using namespace std;
int main ()
{
int age;
double discounted_fare;
cin>>age;
if (12>age);
discounted_fare=age*0.10;
cout<<discounted_fare;
else
discounted_fare=age*0.05;
cout<<discounted_fare;
return 0;
}