#include<cstdio>
#include<iostream>
using namespace std;
int main()
{
    int a;
    float c;
    cin>>a;
    if(a<=150)		
	{
	    	
	 c=a*4463;
	}
		else if(a>=151&&a<=400)
		{
			c+=150*0.4463;
	        c+=(a-150)*0.4663;
			
		}
		else
		{
		    c+=150*0.4463;
	        c+=(400-150)*0.4663;
	        c=(a-400)*0.5663;
		
		 } 
		 printf("%0.1f",c);
		 return 0; 
	}