#include<iostream>
using namespace std;
double f(double m){
if(m<=1500){
return m*3/100;
}else if(m<=4500){
return f(1500)+(m-1500)/10;
}else if(m<=9000){
return f(4500)+(m-4500)/5;
}else if(m<=35000){
return f(9000)+(m-9000)/4;
}else if(m<=55000){
return f(35000)+(m-35000)*3/10;
}else if(m<=80000){
return f(55000)+(m-55000)*35/100;
}else {
return f(80000)+(m-80000)*45/100;
}
}
double ff(double m){
if(m<=1455){
return m*100/97;
}else if(m<=4155){
m+= f(1500);
m-=1500;
m=m*10/9;
m+=1500;
return m;
}else if(m<=7725){
m+= f(4500);
m-=4500;
m=m*10/8;
m+=4500;
return m;
}else if(m<=27255){
m+= f(9000);
m-=9000;
m=m*100/75;
m+=9000;
return m;
}else if(m<=41255){
m+= f(35000);
m-=35000;
m=m*10/7;
m+=35000;
return m;
}else if(m<=57505){
m+= f(55000);
m-=55000;
m=m*100/65;
m+=55000;
return m;
}else {
m+= f(80000);
m-=80000;
m=m*100/55;
m+=80000;
return m;
}
}
int main(){
int t;cin>>t;
if(t<=3500){
cout<<t<<endl;
return 0;
}
t-=3500;
cout<<ff(t)+3500;
//cout<<1500-f(1500)<<endl;
//cout<<4500-f(4500)<<endl;
//cout<<9000-f(9000)<<endl;
//cout<<35000-f(35000)<<endl;
//cout<<55000-f(55000)<<endl;
//cout<<80000-f(80000)<<endl;
return 0;
}