#include<bits/stdc++.h> using namespace std; int main(){ double kwh,df; cin>>kwh; if(kwh<=150)df=kwh0.4463; else if(kwh<=400)df=1500.4463+(kwh-150)0.4663; else if(kwh>400)df=1500.4463+250*0.4663+(kwh-400)*0.5663; cout<<fixed<<setprecision(1)<<df; return 0; }