#include <bits/stdc++.h>
using namespace std;
double j;
int main()
{
	int n;
	cin>>n;
	if(n-150<=0)
		j=n*0.4463;
	else
	{
		if(n-400<=0)
		{
			j=150*0.4463+(n-150)*0.4663;
		}
		else
			j=150*0.4463+(n-150)*0.4663+(n-400)*0.5663;
	}
	printf("%.1f\n",j);
	return 0;
}

请求支援！