#include<bits/stdc++.h> using namespace std;

int main() { int n;

cin>>n;

double price,sum;

if(n<=150)
{
	price=0.4463;
	sum=price*n;
}
else if(n>=151 && n<=400)
{
	price=0.4663;
	sum=(n-150)*price+66.945;
}
else
{
	price=0.5663;
	sum=(n-400)*price+183.52;
}

printf("%.1f",sum);

return 0;

}