#include <bits/stdc++.h>
#include <iomanip>
using namespace std;
int main(){
float all;
cin>>all;
float ans=1;
if(all<=150){
    ans=all*0.4463;
}
if(all>=151&&all<=400){
ans=150*0.4463;
all=all-150;
ans=ans+all*0.4663;
}
if(all>=401){
ans=150*0.4463;
all=all-150;
ans=ans+all*0.4663;
all=all-249;
ans=ans+all*0.5663;
}





cout<<fixed<<setprecision(1)<<ans;
    return 0;
}