include

include

using namespace std;

define L1 66.945

define L2 183.52

int main(void){

int n;
cin>>n;
if (n<=150){
	printf("%.1f",0.4463*n);
}else if(n<=400){
	printf("%.1f",(n-150)*0.4663+L1); 
}else{
	printf("%.1f",L2+(n-400)*0.5663); 		
}		
return 0;

}