#include <bits/stdc++.h> using namespace std;
int main() { double a,b; cin>>a; if(a<=1000) { b=a*0.95; cout<<fixed<<setprecision(2)<<b; } else {

   b=(a-1000)*0.9+1000*0.95;
   cout<<fixed<<setprecision(2)<<b;	
}

return 0;}