#include<cstdio>
#include<iostream>
using namespace std;
int main() {
	long long power;
	double money;
	scanf("%d",power);
	if (power<150) {
		money = power*0.4463;
	} else if (power<400) {
		money = 150*0.4463 + (power - 150)*0.4663;
	} else {
		money = 150*0.4463 + 250*0.4663 + (power - 400)*0.5663;
	}
	printf("%.1lf",money);
	return 0;
}

真的就看着5个RE陷入沉思了