#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;cin>>n;
    cout<<fixed;
    if(n<=150)
    cout<<setprecision(1)<<n*0.4463;
    else if(n<=400)
    cout<<setprecision(1)<<66.945+((n-150)*0.4663);
    else 
    cout<<setprecision(1)<<116.575+((n-400)*0.5663);
}